Combination therapy with an antitumor alkaloid

ABSTRACT

The present invention relates to the combination of PM01183 with several anticancer drugs, in particular other anticancer drugs selected from antitumor platinum coordination complexes, antimetabolites, mitotic inhibitors, anticancer antibiotics, topoisomerase I and/or II inhibitors, proteasome inhibitors, histone deacetylase inhibitors, nitrogen mustard alkylating agents, nitrosourea alkylating agents, nonclassical alkylating agents, estrogen antagonists, androgen antagonists, mTOR inhibitors, tyrosine kinase inhibitors, and other agents selected from aplidine, ET-743, PM02734 and PM00104, and the use of these combinations in the treatment of cancer.

FIELD OF THE INVENTION

The present invention relates to the combination of PM01183 with other anticancer drugs, in particular other anticancer drugs selected from antitumor platinum coordination complexes, antimetabolites, mitotic inhibitors, anticancer antibiotics, topoisomerase I and/or II inhibitors, proteasome inhibitors, histone deacetylase inhibitors, nitrogen mustard alkylating agents, nitrosourea alkylating agents, nonclassical alkylating agents, estrogen antagonists, androgen antagonists, mTOR inhibitors, tyrosine kinase inhibitors, and other agents selected from aplidine, ET-743, PM02734, and PM00104 and the use of these combinations in the treatment of cancer.

BACKGROUND OF THE INVENTION

Cancer develops when cells in a part of the body begin to grow out of control. Although there are many kinds of cancer, they all arise from out-of-control growth of abnormal cells. Cancer cells can invade nearby tissues and can spread through the bloodstream and lymphatic system to other parts of the body. There are several main types of cancer. Carcinoma is a malignant neoplasm, which is an uncontrolled and progressive abnormal growth, arising from epithelial cells. Epithelial cells cover internal and external surfaces of the body, including organs, lining of vessels, and other small cavities. Sarcoma is cancer arising from cells in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that arises in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the bloodstream. Lymphoma and multiple myeloma are cancers that arise from cells of the immune system.

In addition, cancer is invasive and tends to infiltrate the surrounding tissues and give rise to metastases. It can spread directly into surrounding tissues and also may be spread through the lymphatic and circulatory systems to other parts of the body.

Many treatments are available for cancer, including surgery and radiation for localised disease, and chemotherapy. However, the efficacy of available treatments for many cancer types is limited, and new, improved forms of treatment showing clinical benefits are needed. This is especially true for those patients presenting with advanced and/or metastatic disease and for patients relapsing with progressive disease after having been previously treated with established therapies which become ineffective or intolerable due to acquisition of resistance or to limitations in administration of the therapies due to associated toxicities.

Since the 1950s, significant advances have been made in the chemotherapeutic management of cancer. Unfortunately, more than 50% of all cancer patients either do not respond to initial therapy or experience relapse after an initial response to treatment and ultimately die from progressive metastatic disease. Thus, the ongoing commitment to the design and discovery of new anticancer agents is critically important.

Chemotherapy, in its classic form, has been focused primarily on killing rapidly proliferating cancer cells by targeting general cellular metabolic processes, including DNA, RNA, and protein biosynthesis. Chemotherapy drugs are divided into several groups based on how they affect specific chemical substances within cancer cells, which cellular activities or processes the drug interferes with, and which specific phases of the cell cycle the drug affects. The most commonly used types of chemotherapy drugs include: DNA-alkylating drugs (such as cyclophosphamide, ifosfamide, cisplatin, carboplatin, dacarbazine), antimetabolites (5-fluorouracil, capecitabine, 6-mercaptopurine, methotrexate, gemcitabine, cytarabine, fludarabine), mitotic inhibitors (such as paclitaxel, docetaxel, vinblastine, vincristine), anticancer antibiotics (such as daunorubicin, doxorubicin, epirubicin, idarubicin, mitoxantrone), topoisomerase I and/or II inhibitors (such as topotecan, irinotecan, etoposide, teniposide), and hormone therapy (such as tamoxifen, flutamide).

The ideal antitumor drug would kill cancer cells selectively, with a wide index relative to its toxicity towards non-cancer cells and it would also retain its efficacy against cancer cells, even after prolonged exposure to the drug. Unfortunately, none of the current chemotherapies with these agents posses an ideal profile. Most posses very narrow therapeutic indexes and, in addition, cancerous cells exposed to slightly sublethal concentrations of a chemotherapeutic agent may develop resistance to such an agent, and quite often cross-resistance to several other antitumor agents.

PM01183, also known as tryptamicidin, is a synthetic alkaloid which is currently in clinical trials for the treatment of cancer, and has the following chemical structure:

PM01183 has demonstrated a highly potent in vitro activity against solid and non-solid tumour cell lines as well as a significant in vivo activity in several xenografted human tumor cell lines in mice, such as those for breast, kidney and ovarian cancer. PM01183 exerts its anticancer effects through the covalent modification of guanines in the DNA minor groove that eventually give rise to DNA double-strand break, S-phase arrest and apoptosis in cancer cells. Further information regarding this compound can be found in WO 03/01427; 100^(th) AACR Annual Meeting, Apr. 18-22, 2009, Denver, CO, Abstract Nr. 2679 and Abstract Nr. 4525; and Leal J F M et al. Br. J. Pharmacol. 2010, 161, 1099-1110.

Since cancer is a leading cause of death in animals and humans, several efforts have been and are still being undertaken in order to obtain a therapy active and safe to be administered to patients suffering from a cancer. The problem to be solved by the present invention is to provide anticancer therapies that are useful in the treatment of cancer.

SUMMARY OF THE INVENTION

The present invention establishes that PM01183 potentiates the antitumor activity of other anticancer agents, in particular other anticancer drugs selected from antitumor platinum coordination complexes, antimetabolites, mitotic inhibitors, anticancer antibiotics, topoisomerase I and/or II inhibitors, proteasome inhibitors, histone deacetylase inhibitors, nitrogen mustard alkylating agents, nitrosourea alkylating agents, nonclassical alkylating agents, estrogen antagonists, androgen antagonists, mTOR inhibitors, tyrosine kinase inhibitors, and other agents selected from aplidine, ET-743, PM02734 and PM00104. Therefore PM01183 and said other anticancer agents can be successfully used in combination therapy for the treatment of cancer.

Thus, this invention is directed to pharmaceutical compositions, kits, methods for the treatment of cancer using these combination therapies and uses of both drugs in the treatment of cancer and in the manufacture of medicaments for combination therapies.

In accordance with one aspect of this invention, we provide effective combination therapies for the treatment of cancer based on PM01183, or a pharmaceutically acceptable salt thereof, and using another anticancer drug as defined above.

In another embodiment, the invention is directed to PM01183, or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer comprising administering a therapeutically effective amount of PM01183, or a pharmaceutical acceptable salt thereof, in combination with a therapeutically effective amount of another anticancer drug.

In another embodiment, the invention encompasses a method of treating cancer comprising administering to a patient in need of such treatment a therapeutically effective amount of PM01183, or a pharmaceutically acceptable salt thereof, and a therapeutically effective amount of another anticancer drug.

In another aspect, the invention encompasses a method of increasing or potentiating the therapeutic efficacy of an anticancer drug in the treatment of cancer, which comprises administering to a patient in need thereof a therapeutically effective amount of PM01183, or a pharmaceutically acceptable salt thereof, in conjunction with this other anticancer drug.

In another embodiment, the invention encompasses the use of PM01183, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of cancer by combination therapy employing PM01183, or a pharmaceutically acceptable salt thereof, with another anticancer drug.

In a further aspect, the invention encompasses a pharmaceutical composition comprising PM01183, or a pharmaceutically acceptable salt thereof, and/or another anticancer drug, and a pharmaceutically acceptable carrier, to be used in combination therapy for the treatment of cancer.

The invention also encompasses a kit for use in the treatment of cancer which comprises a dosage form of PM01183, or a pharmaceutically acceptable salt thereof, and/or a dosage form of another anticancer drug, and instructions for the use of both drugs in combination.

In one preferred aspect, the present invention is concerned with synergistic combinations of PM01183, or a pharmaceutically acceptable salt thereof, with another anticancer drug.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1-20 . In vitro activity data of PM01183 in combination with oxaliplatin, 5-fluorouracil, gemcitabine, paclitaxel, docetaxel, vincristine, daunorubicin, mitomycin C, actinomycin D, topotecan, etoposide, bortezomib, vorinostat, cyclophosphamide, carmustine, dacarbazine, temsirolimus, erlotinib, ET-743 and PM00104 respectively against A549 cells.

FIG. 21-41 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, cytarabine, gemcitabine, docetaxel, vincristine, vinorelbine, daunorubicin, mitomycin C, actinomycin D, topotecan, etoposide, vorinostat, cyclophosphamide, dacarbazine, temsirolimus, erlotinib, aplidine, ET-743, PM02734 and PM00104 respectively against A673 cells.

FIG. 42-56 . In vitro activity data of PM01183 in combination with cisplatin, 5-fluorouracil, cytarabine, methotrexate, daunorubicin, doxorubicin, mitomycin C, topotecan, irinotecan, etoposide, dacarbazine, temsirolimus, ET-743, PM02734 and PM00104 respectively against SK-MEL-2 cells.

FIG. 57-80 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, 5-fluorouracil, cytarabine, gemcitabine, methotrexate, docetaxel, paclitaxel, vinorelbine, daunorubicin, doxorubicin, mitomycin C, actinomycin D, topotecan, irinotecan, etoposide, bortezomib, vorinostat, flutamide, temsirolimus, erlotinib, ET-743, PM02734 and PM00104 respectively against PC-3 cells.

FIG. 81-98 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, cytarabine, gemcitabine, methotrexate, daunorubicin, doxorubicin, actinomycin D, topotecan, irinotecan, etoposide, bortezomib, vorinostat, temsirolimus, erlotinib, ET-743, PM02734 and PM00104 respectively against PANC-1 cells.

FIG. 99-123 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, 5-fluorouracil, cytarabine, gemcitabine, methotrexate, paclitaxel, vincristine, vinorelbine, daunorubicin, doxorubicin, actinomycin D, topotecan, irinotecan, etoposide, bortezomib, vorinostat, cyclophosphamide, dacarbazine, temsirolimus, erlotinib, aplidine, ET-743, PM02734 and PM00104 respectively against HGC-27 cells.

FIG. 124-150 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, 5-fluorouracil, cytarabine, gemcitabine, methotrexate, docetaxel, paclitaxel, vincristine, vinorelbine, daunorubicin, doxorubicin, actinomycin D, mitomycin C, topotecan, irinotecan, etoposide, vorinostat, cyclophosphamide, carmustine, dacarbazine, temsirolimus, erlotinib, aplidine, ET-743, PM02734 and PM00104 respectively against IGROV-1 cells.

FIG. 151-170 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, cytarabine, gemcitabine, methotrexate, docetaxel, paclitaxel, vincristine, vinorelbine, daunorubicin, doxorubicin, topotecan, irinotecan, etoposide, bortezomib, cyclophosphamide, erlotinib, ET-743 and PM00104 respectively against HEP-G2 cells.

FIG. 171-197 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, 5-fluorouracil, cytarabine, gemcitabine, methotrexate, docetaxel, paclitaxel, vincristine, vinorelbine, daunorubicin, doxorubicin, actinomycin D, mitomycin C, topotecan, irinotecan, etoposide, vorinostat, cyclophosphamide, carmustine, dacarbazine, tamoxifen, temsirolimus, erlotinib, ET-743, PM02734 and PM00104 respectively against MDA-MB-231 cells.

FIG. 198-219 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, cytarabine, gemcitabine, docetaxel, vinorelbine, daunorubicin, doxorubicin, actinomycin D, mitomycin C, topotecan, irinotecan, etoposide, bortezomib, vorinostat, cyclophosphamide, dacarbazine, temsirolimus, erlotinib, aplidine and PM02734 respectively against HT-29 cells.

FIG. 220-242 . In vitro activity data of PM01183 in combination with cisplatin, 5-fluorouracil, cytarabine, gemcitabine, methotrexate, docetaxel, vincristine, vinorelbine, daunorubicin, doxorubicin, actinomycin D, mitomycin C, topotecan, irinotecan, etoposide, vorinostat, cyclophosphamide, dacarbazine, erlotinib, aplidine, ET-743, PM02734 and PM00104 respectively against RXF-393 cells.

FIG. 243-262 . In vitro activity data of PM01183 in combination with cisplatin, oxaliplatin, gemcitabine, methotrexate, docetaxel, vincristine, daunorubicin, doxorubicin, topotecan, irinotecan, etoposide, bortezomib, vorinostat, dacarbazine, temsirolimus, erlotinib, aplidine, ET-743 and PM02734 respectively against U87-MG cells.

FIG. 263 . Tumor volume evaluation of A2780 tumors in mice treated with placebo, PM01183, paclitaxel and PM01183 plus paclitaxel.

FIG. 264 . Tumor volume evaluation of A2780 tumors in mice treated with placebo, PM01183, vinorelbine and PM01183 plus vinorelbine.

FIG. 265 . Tumor volume evaluation of A2780 tumors in mice treated with placebo, PM01183, doxorubicin and PM01183 plus doxorubicin.

FIG. 266 . Tumor volume evaluation of HGC-27 tumors in mice treated with placebo, PM01183, cisplatin and PM01183 plus cisplatin.

FIG. 267 . Tumor volume evaluation of HGC-27 tumors in mice treated with placebo, PM01183, 5-fluorouracil and PM01183 plus 5-fluorouracil.

FIG. 268 . Tumor volume evaluation of SW1990 tumors in mice treated with placebo, PM01183, gemcitabine and PM01183 plus gemcitabine.

FIG. 269 . Tumor volume evaluation of U87-MG tumors in mice treated with placebo, PM01183, temozolomide and PM01183 plus temozolomide.

FIG. 270 . Tumor volume evaluation of H460 tumors in mice treated with placebo, PM01183, irinotecan and PM01183 plus irinotecan.

FIG. 271 . Tumor volume evaluation of HT1080 tumors in mice treated with placebo, PM01183, dacarbazine and PM01183 plus dacarbazine.

FIG. 272 . Tumor volume evaluation of HT-29 tumors in mice treated with placebo, PM01183, irinotecan and PM01183 plus irinotecan.

FIG. 273 . Effects of the combination of PM01183 with methotrexate in JURKAT cell line.

FIG. 274 . Effects of the combination of PM01183 with methotrexate in MOLT-4 cell line.

FIG. 275 . Effects of the combination of PM01183 with daunorubicin in JURKAT cell line.

FIG. 276 . Effects of the combination of PM01183 with aplidine in JURKAT cell line.

FIG. 277 . Effects of the combination of PM01183 with aplidine in MOLT-4 cell line.

FIG. 278 . Effects of the combination of PM01183 with ET-743 in JURKAT cell line.

FIG. 279 . Effects of the combination of PM01183 with ET-743 in MOLT-4 cell line.

FIG. 280 . Effects of the combination of PM01183 with PM00104 in JURKAT cell line.

FIG. 281 . Effects of the combination of PM01183 with PM00104 in MOLT-4 cell line.

FIG. 282 . Effects of the combination of PM01183 with PM02734 in JURKAT cell line.

FIG. 283 . Effects of the combination of PM01183 with PM02734 in MOLT-4 cell line.

FIG. 284 . Effects of the combination of PM01183 with cytarabine in RAMOS cell line.

FIG. 285 . Effects of the combination of PM01183 with methotrexate in RAMOS cell line.

FIG. 286 . Effects of the combination of PM01183 with methotrexate in U-937 cell line.

FIG. 287 . Effects of the combination of PM01183 with gemcitabine in RAMOS cell line.

FIG. 288 . Effects of the combination of PM01183 with gemcitabine in U-937 cell line.

FIG. 289 . Effects of the combination of PM01183 with daunorubicin in RAMOS cell line.

FIG. 290 . Effects of the combination of PM01183 with daunorubicin in U-937 cell line.

FIG. 291 . Effects of the combination of PM01183 with ET-743 in RAMOS cell line.

FIG. 292 . Effects of the combination of PM01183 with ET-743 in U-937 cell line.

FIG. 293 . Effects of the combination of PM01183 with PM00104 in RAMOS cell line.

FIG. 294 . Effects of the combination of PM01183 with PM00104 in U-937 cell line.

FIG. 295 . Effects of the combination of PM01183 with PM02734 in RAMOS cell line.

FIG. 296 . Effects of the combination of PM01183 with PM02734 in U-937 cell line.

DETAILED DESCRIPTION OF THE INVENTION

We surprisingly found that PM01183 greatly enhances the anticancer activity of other anticancer drugs when these anticancer drugs are combined with PM01183. Thus, the present invention is directed to provide an efficacious treatment of cancer based on the combination of PM01183, or a pharmaceutically acceptable salt thereof, with another anticancer drug.

In the present application, by “cancer” it is meant to include tumors, neoplasias, and any other malignant disease having as cause malignant tissue or cells.

The term “treating”, as used herein, unless otherwise indicated, means reversing, alleviating, or inhibiting the progress of the disease or condition to which such term applies, or one or more symptoms of such disorder or condition. The term “treatment”, as used herein, unless otherwise indicated, refers to the act of treating as “treating” is defined immediately above.

The term “combination” as used throughout the specification, is meant to encompass the administration to a patient suffering from cancer of the referred therapeutic agents in the same or separate pharmaceutical formulations, and at the same time or at different times. If the therapeutic agents are administered at different times they should be administered sufficiently close in time to provide for the potentiating or synergistic response to occur.

As mentioned above, PM01183 is a synthetic alkaloid, having the following structure:

The term “PM01183” is intended here to cover any pharmaceutically acceptable salt, solvate, hydrate, prodrug, or any other compound which, upon administration to the patient is capable of providing (directly or indirectly) the compound as described herein. The preparation of salts, solvates, hydrates, and prodrugs can be carried out by methods known in the art.

Pharmaceutically acceptable salts can be synthesized from the parent compound, which contains a basic or acidic moiety, by conventional chemical methods. Generally, such salts are, for example, prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent or in a mixture of the two. Generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol or acetonitrile are preferred. Examples of the acid addition salts include mineral acid addition salts such as, for example, hydrochloride, hydrobromide, hydroiodide, sulphate, nitrate, phosphate, and organic acid addition salts such as, for example, acetate, trifluoroacetate, maleate, fumarate, citrate, oxalate, succinate, tartrate, malate, mandelate, methanesulphonate and p-toluenesulphonate. Examples of the alkali addition salts include inorganic salts such as, for example, sodium, potassium, calcium and ammonium salts, and organic alkali salts such as, for example, ethylenediamine, ethanolamine, N,N-dialkylenethanolamine, triethanolamine and basic aminoacids salts.

Any compound that is a prodrug of PM01183 is within the scope and spirit of the invention. The term “prodrug” is used in its broadest sense and encompasses those derivatives that are converted in vivo to PM01183. The prodrug can hydrolyze, oxidize, or otherwise react under biological conditions to provide PM01183. Examples of prodrugs include, but are not limited to, derivatives and metabolites of PM01183 that include biohydrolyzable moeities such as biohydrolyzable amides, biohydrolyzable esters, biohydrolyzable carbamates, biohydrolyzable carbonates, biohydrolyzable ureides, and biohydrolyzable phosphate analogues. Prodrugs can typically be prepared using well-known methods, such as those described by Burger in “Medicinal Chemistry and Drug Discovery” 6th ed. (Donald J. Abraham ed., 2001, Wiley) and “Design and Applications of Prodrugs” (H. Bundgaard ed., 1985, Harwood Academic Publishers).

In addition, any drug referred to herein may be in amorphous form or crystalline form either as free compound or as solvates (e.g. hydrates) and it is intended that both forms are within the scope of the present invention. Methods of solvation are generally known within the art.

Moreover, PM01183 for use in accordance with the present invention may be prepared following the synthetic process such as the one disclosed in WO 03/014127, which is incorporated herein by reference.

Pharmaceutical compositions of PM01183, or of a pharmaceutically acceptable salt thereof, that can be used include solutions, suspensions, emulsions, lyophilised compositions, etc., with suitable excipients for intravenous administration. Preferably, PM01183 may be supplied and stored as a sterile lyophilized product, comprising PM01183 and excipients in a formulation adequate for therapeutic use. For further guidance on pharmaceutical compositions of PM01183, or a pharmaceutically acceptable salt thereof, see for example the formulations described in WO 2006/046079, which is incorporated herein by reference.

Administration of PM01183, or a pharmaceutically acceptable salt thereof, or pharmaceutical compositions comprising the compound is preferably by intravenous infusion. Infusion times of up to 72 hours can be used, more preferably between 1 and 24 hours, with either about 1 hour or about 3 hours most preferred. Short infusion times which allow treatment to be carried out without an overnight stay in hospital are especially desirable. However, infusion may be around 24 hours or even longer if required.

Preferably the administration of PM01183 is performed in cycles. In a preferred administration schedule an intravenous infusion of PM01183 is given to the patients the first week of each cycle and the patients are allowed to recover for the remainder of the cycle. The preferred duration of each cycle is of either 3 or 4 weeks. Multiple cycles can be given as needed. Administration of PM01183, or a pharmaceutically acceptable salt thereof, by intravenous infusion during about 1 hour once every 3 weeks is the most preferred administration schedule, although other protocols can be devised as variations.

In the present invention, particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with another anticancer drug selected from antitumor platinum coordination complexes, antimetabolites, mitotic inhibitors, anticancer antibiotics, topoisomerase I and/or II inhibitors, proteasome inhibitors, histone deacetylase inhibitors, nitrogen mustard alkylating agents, nitrosourea alkylating agents, nonclassical alkylating agents, estrogen antagonists, androgen antagonists, mTOR inhibitors, tyrosine kinase inhibitors, and other agents selected from aplidine, ET-743, PM02734 and PM00104 in the treatment of cancer.

Particularly preferred cancer types are those selected from lung cancer, sarcoma, malignant melanoma, bladder carcinoma, prostate cancer, pancreas carcinoma, thyroid cancer, gastric carcinoma, ovarian cancer, hepatoma (also known as liver cancer), breast cancer, colorectal cancer, kidney cancer, esophageal cancer, neuroblastoma, brain cancer, cervical cancer, anal cancer, testicular cancer, leukemia, multiple myeloma and lymphoma.

In a preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with an antitumor platinum coordination complex in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, brain cancer and lymphoma. This chemotherapeutic group includes, but is not limited to cisplatin, oxaliplatin, carboplatin, triplatin tetranitrate (BBR3464), satraplatin, tetraplatin, ormiplatin, iproplatin, nedaplatin and lobaplatin. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with cisplatin, oxaliplatin, carboplatin, triplatin tetranitrate, satraplatin, tetraplatin, ormiplatin, iproplatin, nedaplatin and lobaplatin, and even more preferred is the combination with cisplatin and oxaliplatin in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with an antimetabolite in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, malignant melanoma, bladder carcinoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, esophageal cancer, brain cancer, anal cancer, leukaemia and lymphoma. This chemotherapeutic group includes, but is not limited to gemcitabine, cytarabine, capecitabine, decitabine, floxuridine, fludarabine, aminopterin, methotrexate, pemetrexed, raltitrexed, cladribine, clofarabine, mercaptopurine, pentostatin, and thioguanine. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with 5-fluorouracil, gemcitabine, cytarabine, capecitabine, decitabine, floxuridine, fludarabine, aminopterin, methotrexate, pemetrexed, raltitrexed, cladribine, clofarabine, mercaptopurine, pentostatin, and thioguanine, and even more preferred is the combination with 5-fluorouracil, gemcitabine, cytarabine and methotrexate in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, brain cancer, leukemia and lymphoma.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a mitotic inhibitor in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, prostate cancer, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, brain cancer, leukemia, and lymphoma. This chemotherapeutic group includes, but is not limited to paclitaxel, docetaxel, vinblastine, vincristine, vindesine, and vinorelbine. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with paclitaxel, docetaxel, vinblastine, vincristine, vindesine, and vinorelbine, and even more preferred is the combination with paclitaxel, docetaxel, vincristine and vinorelbine in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, prostate cancer, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with an anticancer antibiotic in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, malignant melanoma, bladder carcinoma, prostate cancer, pancreas carcinoma, thyroid cancer, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, neuroblastoma, brain cancer, anal cancer, testicular cancer, leukemia, multiple myeloma and lymphoma. This chemotherapeutic group includes, but is not limited to daunorubicin, doxorubicin, epirubicin, idarubicin, mitoxantrone, pixantrone, valrubicin, mitomycin C, bleomycin, actinomycin A and mithramycin. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with daunorubicin, doxorubicin, epirubicin, idarubicin, mitoxantrone, pixantrone, valrubicin, mitomycin C, bleomycin, actinomycin D and mithramycin, and even more preferred is the combination with daunorubicin, doxorubicin, mitomycin C and actinomycin D in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, brain cancer, leukemia and lymphoma.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a topoisomerase I and/or II inhibitor in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, neuroblastoma, brain cancer, cervical cancer, testicular cancer, leukemia and lymphoma. This chemotherapeutic group includes, but is not limited to topotecan, SN-38, irinotecan, camptothecin, rubitecan, etoposide, amsacrine and teniposide. Particularly preferred is the combination of PM00104, or a pharmaceutically acceptable salt thereof, with topotecan, SN-38, irinotecan, camptothecin, rubitecan, etoposide, amsacrine and teniposide, and even more preferred is the combination with topotecan, irinotecan and etoposide in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a proteosome inhibitor in the treatment of cancer, and more particularly in the treatment of lung cancer, prostate cancer, pancreas carcinoma, gastric carcinoma, hepatoma, colorectal cancer, brain cancer, multiple myeloma and lymphoma. This chemotherapeutic group includes, but is not limited to bortezomib, disulfiram, epigallocatechin gallate, and salinosporamide A. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with bortezomib, disulfiram, epigallocatechin gallate, and salinosporamide A, and even more preferred is the combination with bortezomib in the treatment of cancer, and more particularly in the treatment of lung cancer, prostate cancer, pancreas carcinoma, gastric carcinoma, hepatoma, colorectal cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a histone deacetylase inhibitor in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer, kidney cancer, brain cancer and lymphoma. This chemotherapeutic group includes, but is not limited to romidepsin, panobinostat, vorinostat, mocetinostat, belinostat, entinostat, resminostat, PCI-24781, AR-42, CUDC-101, and valproic acid. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with romidepsin, panobinostat, vorinostat, mocetinostat, belinostat, entinostat, resminostat, PCI-24781, AR-42, CUDC-101, and valproic acid, and even more preferred is the combination with vorinostat in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer, kidney cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a nitrogen mustard alkylating agent in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, bladder carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, leukemia, multiple myeloma and lymphoma. This chemotherapeutic group includes, but is not limited to melphalan, ifosfamide, chlorambucil, cyclophosphamide, mechlorethamine, uramustine, estramustine and bendamustine. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with melphalan, ifosfamide, chlorambucil, cyclophosphamide, mechlorethamine, uramustine, estramustine and bendamustine, and even more preferred is the combination with cyclophosphamide in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer and kidney cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a nitrosourea alkylating agent in the treatment of cancer, and more particularly in the treatment of lung cancer, ovarian cancer, breast cancer, brain cancer, multiple myeloma and lymphoma. This chemotherapeutic group includes, but is not limited to lomustine, semustine, carmustine, fotemustine and streptozotocin. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with lomustine, semustine, carmustine, fotemustine and streptozotocin, and even more preferred is the combination with carmustine in the treatment of cancer, and more particularly in the treatment of lung cancer, ovarian cancer and breast cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a nonclassical alkylating agent in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, malignant melanoma, pancreas carcinoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer, kidney cancer, brain cancer, leukemia and lymphoma. This chemotherapeutic group includes, but is not limited to procarbazine, dacarbazine, temozolomide and altretamine. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with procarbazine, dacarbazine, temozolomide and altretamine, and even more preferred is the combination with dacarbazine and tezolomide in the treatment of lung cancer, sarcoma, malignant melanoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer, kidney cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with an estrogen antagonist in the treatment of cancer, and more particularly in the treatment of breast cancer. This chemotherapeutic group includes, but is not limited to toremifene, fulvestrant, tamoxifen and nafoxidine. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with toremifene, fulvestrant, tamoxifen and nafoxidine, and even more preferred is the combination with tamoxifen in the treatment of breast cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with an androgen antagonist in the treatment of cancer, and more particularly in the treatment of prostate cancer. This chemotherapeutic group includes, but is not limited to bicalutamide, flutamide, MDV3100 and nilutamide. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with bicalutamide, flutamide, MDV3100 and nilutamide, and even more preferred is the combination with flutamide in the treatment of prostate cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a mTOR inhibitor in the treatment of cancer, and more particularly in the treatment of lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer, kidney cancer and brain cancer. This chemotherapeutic group includes, but is not limited to sirolimus, temsirolimus, everolimus, ridaforolimus, KU-0063794 and WYE-354. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with sirolimus, temsirolimus, everolimus, ridaforolimus, KU-0063794 and WYE-354, and even more preferred is the combination with temsirolimus in the treatment of lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with a tyrosine kinase inhibitor in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer and brain cancer. This chemotherapeutic group includes, but is not limited to erlotinib, sorafenib, axitinib, bosutinib, cediranib, crizotinib, dasatinib, gefitinib, imatinib, canertinib, lapatinib, lestaurtinib, neratinib, nilotinib, semaxanib, sunitinib, vatalanib and vandetanib. Particularly preferred is the combination of PM01183, or a pharmaceutically acceptable salt thereof, with erlotinib, sorafenib, axitinib, bosutinib, cediranib, crizotinib, dasatinib, gefitinib, imatinib, canertinib, lapatinib, lestaurtinib, neratinib, nilotinib, semaxanib, sunitinib, vatalanib and vandetanib, and even more preferred is the combination with erlotinib in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer and brain cancer.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with aplidine in the treatment of cancer, and more particularly in the treatment of a cancer selected from sarcoma, gastric carcinoma, ovarian cancer, colorectal cancer, kidney cancer, brain cancer and leukemia.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with ET-743 (trabectedin) in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, kidney cancer, leukemia and lymphoma.

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with PM02734 in the treatment of cancer, and more particularly in the treatment of a cancer selected from sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, breast cancer, colorectal cancer, kidney cancer, brain cancer, leukemia and lymphoma.

PM02734 ((4S)-MeHex-D-Val-L-Thr-L-Val-D-Val-D-Pro-L-Orn-D-allo-Ile-cyclo(D-allo-Thr-D-allo-Ile-D-Val-L-Phe-Z-Dhb-L-Val)) is a synthetic depsipeptide related to the family of kahalalide compounds, which is currently in clinical trials for the treatment of cancer. This compound is the subject of WO 2004/035613 and has the following structure:

In another preferred embodiment, the invention is directed to the combination of PM01183, or a pharmaceutically acceptable salt thereof, with PM00104 in the treatment of cancer, and more particularly in the treatment of a cancer selected from lung cancer, sarcoma, malignant melanoma, prostate cancer, pancreas carcinoma, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, kidney cancer, leukemia and lymphoma.

PM00104 is a synthetic alkaloid related to jorumycin and renieramycins, and also to safracin and saframycin compounds, which is currently in clinical trials for the treatment of cancer, and has the following structure:

For further details on PM00104 see WO 01/87894.

The invention includes any pharmaceutically acceptable salt of any drug referred to herein, which can be synthesized from the parent compound by conventional chemical methods as disclosed before.

In one embodiment, the invention relates to synergistic combinations employing PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above. An indication of synergism can be obtained by testing the combinations and analyzing the results, for example by the Chou-Talalay method or by any other suitable method, such as those provided in the Examples section.

The possible favorable outcomes for synergism include 1) increasing the efficacy of the therapeutic effect, 2) decreasing the dosage but increasing or maintaining the same efficacy to avoid toxicity, 3) minimizing or slowing down the development of drug resistance, and 4) providing selective synergism against target (or efficacy synergism) versus host (or toxicity antagonism). Accordingly, in a combination of two chemotherapeutic agents having synergism, the treatment regimen will be different of those in which the combination of the two drugs shows only an additive effect. In this regard, if there is synergism less dosage of one or both of the agents (compared with the amounts used in single therapy) may be required to obtain the same or even a greater efficacy, and the possible toxic side effects may be reduced or even avoided. Alternatively, if the dosage of both drugs in the combination is the same as those when given alone (as single agents), an increase in efficacy of the combination can be expected. Therefore, the existence of synergism in a given drug combination will modify the length of the treatment and/or the treatment regimen.

In another embodiment, the invention relates to a method of increasing or potentiating the therapeutic efficacy of an anticancer drug selected from the list of drugs given above in the treatment of cancer, which comprises administering to a patient in need thereof a therapeutically effective amount of PM01183, or a pharmaceutically acceptable salt thereof, in conjunction with this other anticancer drug. An indication of increase or potentiation of the therapeutic efficacy can be obtained by testing the combinations and analyzing the results, for example the tumor growth inhibition. This tumor growth inhibition can be assessed by comparing the mean tumor volume of the treatment combining the two drugs (PM01183 and the other drug) with those of the other drug monotherapy treatment. In this regard, increase or potentiation of the therapeutic efficacy is determined when the response of the combination therapy is greater than the best response of the most active drug administered as single agent (monotherapy) on the same schedule and dose as used in the combination therapy. This aspect of the invention is further illustrated in the Examples section, specifically in Examples 13-19.

In another aspect, the invention is directed to the use of PM01183, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of cancer by combination therapy employing PM01183, or a pharmaceutically acceptable salt thereof, with another anticancer drug selected from the list of drugs given above.

In a further aspect, the invention is directed to a method for the treatment of cancer comprising administering to a patient in need of such treatment a therapeutically effective amount of PM01183, or pharmaceutically acceptable salt thereof, in combination with a therapeutically effective amount of another anticancer drug selected from the list of drugs given above.

In another aspect, the invention is directed to PM01183, or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer comprising administering a therapeutically effective amount of PM01183, or a pharmaceutical acceptable salt thereof, in combination with a therapeutically effective amount of another anticancer drug selected from the list of drugs given above.

According to the present invention, PM01183, or a pharmaceutically acceptable salt thereof, and the other anticancer drug may be provided in the same medicament or as separate medicaments for administration at the same time or at different times. Preferably, PM01183, or a pharmaceutically acceptable salt thereof, and the other anticancer drug are provided as separate medicaments for administration at different times. When administered separately and at different times, either PM01183, or a pharmaceutically acceptable salt thereof, or the other anticancer drug, may be administered first. In addition, both drugs can be administered in the same day or at different days, and they can be administered using the same schedule or at different schedules during the treatment cycle. Additionally, the administration of both drugs can be done by using the same route of administration or different routes. For instance, both drugs can be administered by intravenous administration or, alternatively, one drug can be administered orally and the other one by intravenous administration.

Thus, the pharmaceutical compositions of the present invention may comprise all the components (drugs) in a single pharmaceutically acceptable formulation or, alternatively, the components may be formulated separately and administered in combination with one another. Various pharmaceutically acceptable formulations well known to those of skill in the art can be used in the present invention. Moreover, selection of an appropriate formulation for use in the present invention can be performed by those skilled in the art by taking into account the route of administration and the solubility characteristics of the components of the composition.

The correct dosage of both drugs in combination will vary according to the particular formulation, the mode of application, and the particular site, patient and tumour being treated. Other factors like age, body weight, sex, diet, time of administration, rate of excretion, condition of the patient, other drug combinations, reaction sensitivities and severity of the disease shall be taken into account. Administration can be carried out continuously or periodically within the maximum tolerated dose.

The combination of the invention may be used alone or in combination with one or more of a variety of anticancer agents or supportive care agents.

In addition, depending on the type of tumor and the development stage of the disease, anticancer effects of the treatments of the present invention include, but are not limited to, inhibition of tumor growth, tumor growth delay, regression of tumor, shrinkage of tumor, increased time to regrowth of tumor on cessation of treatment, slowing of disease progression, and prevention of metastasis. It is expected that when a treatment of the present invention is administered to a patient, such as a human patient, in need of such treatment, said treatment will produce an effect, as measured by, for example, the extent of the anticancer effect, the response rate, the time to disease progression, or the survival rate. In particular, the treatments of the invention are suited for human patients, especially those who are relapsing or refractory to previous chemotherapy. First line therapy is also envisaged.

In another aspect, the present invention is directed to a kit for use in the treatment of cancer, comprising a supply of PM01183, or a pharmaceutically acceptable salt thereof, in dosage units for at least one cycle, and printed instructions for the use of PM01183, or a pharmaceutically acceptable salt thereof, with another anticancer drug selected from the list of drugs given above in combination.

In a related aspect, the present invention is directed to a kit for use in the treatment of cancer, comprising a supply of PM01183, or a pharmaceutically acceptable salt thereof, in dosage units for at least one cycle, a supply of another anticancer drug selected from the list of drugs given above in dosage units for at least one cycle, and printed instructions for the use of both drugs in combination.

In another aspect, the present invention also provides a pharmaceutical composition comprising PM01183, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient, for use in combination with another anticancer drug selected from the list of drugs given above in the treatment of cancer.

In a further aspect, the present invention also provides a pharmaceutical composition comprising PM01183, or a pharmaceutically acceptable salt thereof, another anticancer drug selected from the list of drugs given above, and a pharmaceutically acceptable carrier. This pharmaceutical composition is preferable for use in the treatment of cancer.

In another aspect, the invention further provides for the use of PM01183, or a pharmaceutically acceptable salt thereof, in the preparation of a composition for use in combination with another anticancer drug selected from the list of drugs given above in the treatment of cancer.

In another aspect, the invention further provides for the use of PM01183, or a pharmaceutically acceptable salt thereof, for the treatment of cancer, in combination therapy with another anticancer drug selected from the list of drugs given above.

In one embodiment, cancer cells are contacted, or otherwise treated, with a combination of PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above. The cancer cells are preferably human and include carcinoma cells, sarcoma cells, leukemia cells, lymphoma cells, and myeloma cells. More preferably, the cancer cells are cells of lung cancer, sarcoma, malignant melanoma, bladder carcinoma, prostate cancer, pancreas carcinoma, thyroid cancer, gastric carcinoma, ovarian cancer, hepatoma, breast cancer, colorectal cancer, kidney cancer, esophageal cancer, neuroblastoma, brain cancer, cervical cancer, anal cancer, testicular cancer, leukemia, multiple myeloma and lymphoma. In addition, the combination provides a synergistic inhibitory effect against the cancer cells, particularly against the human cancer cells mentioned above.

For example, the combination inhibits proliferation or survival of contacted cancer cells. A lower level of proliferation or survival of the contacted cancer cells compared to the non-contacted cancer cells supports the combination of PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above as being effective for treating a patient with cancer.

In another aspect, the invention provides for a method for inhibiting the growth of cancer cells comprising contacting said cancer cells with an effective amount of PM01183, or a pharmaceutically acceptable salt thereof, in combination with another anticancer drug selected from the list of drugs given above.

In another aspect, the invention provides for a method for inhibiting the growth of cancer cells comprising contacting said cancer cells with a synergistic combination of PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above, wherein said combination provides improved inhibition against cancer cell growth as compared to (i) PM01183, or a pharmaceutically acceptable salt thereof, in the absence of the other anticancer drug, or (ii) the other anticancer drug in the absence of PM01183.

In another aspect, the invention provides for a pharmaceutical composition comprising a synergistic combination of PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above for inhibiting the growth of cancer cells, wherein said combination provides improved inhibition against cancer cell growth as compared to (i) PM01183, or a pharmaceutically acceptable salt thereof, in the absence of the other anticancer drug, or (ii) the other anticancer drug in the absence of PM01183.

In another embodiment, the combination of PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above inhibits tumor growth or reduces the size of a tumor in vivo. In particular, the combination inhibits in vivo growth and/or reduces the size of carcinoma, sarcoma, leukemia, lymphoma, and myeloma. Preferably, the combination inhibits in vivo tumor growth of lung, sarcoma, malignant melanoma, bladder, prostate, pancreas, thyroid, gastric, ovarian, hepatoma, breast, colorectal, kidney, esophageal, neuroblastoma, brain, cervical, anal, testicular, leukemia, multiple myeloma and lymphoma tumours.

For example, these combinations inhibit tumor growth or reduce the size of human cancer xenografts, particularly human gastric, pancreas, sarcoma, lung, colorectal and ovary tumors xenografts, in animal models. A reduced growth or reduced size of human cancer xenografts in animal models administered with these combinations further supports the combination of PM01183, or a pharmaceutically acceptable salt thereof, and another anticancer drug selected from the list of drugs given above as being effective for treating a patient with cancer.

Therefore, in another aspect, the invention provides for a method for reducing the size of a tumor, comprising administering an effective amount of PM01183, or a pharmaceutically acceptable salt thereof, in combination with another anticancer drug selected from the list of drugs given above.

In another aspect, the invention provides for a method for inhibiting tumor growth, comprising administering an effective amount of PM01183, or a pharmaceutically acceptable salt thereof, in combination with another anticancer drug selected from the list of drugs given above.

The following examples further illustrate the invention. These examples should not be interpreted as a limitation of the scope of the invention.

To provide a more concise description, some of the quantitative expressions given herein are not qualified with the term “about”. It is understood that, whether the term “about” is used explicitly or not, every quantity given herein is meant to refer to the actual given value, and it is also meant to refer to the approximation to such given value that would reasonably be inferred based on the ordinary skill in the art, including equivalents and approximations due to the experimental and/or measurement conditions for such given value.

EXAMPLES Example 1. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Lung Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of lung carcinoma.

The following agents were evaluated in combination with PM01183: oxaliplatin, carmustine, cyclophosphamide, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil (5-FU), gemcitabine, paclitaxel, docetaxel, vincristine, daunorubicin, actinomycin D, topotecan, etoposide, bortezomib, vorinostat, dacarbazine, temsirolimus, erlotinib, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C. Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

A549 was the human lung carcinoma cell line selected for this assay. A549 cells were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug in A549 cells after 72 hours of drug exposure.         Briefly, cells were harvested and seeded in 96 well microtiter         plates at a density of 5,000 cells in 150 μL of culture medium         and incubated for 24 hours in drug-free medium before treatment         with vehicle alone or test compounds for 72 h.

The cytotoxic effect was measured by the MTT reduction assay, in which 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole, which is reduced to purple formazan in the mitochondria of living cells, was used. MTT (50 μL of 1 mg/mL stock solution) was added to the wells and incubated for 8 hours at 37° C. until formazan crystals were formed. After gently removing the culture medium, DMSO was added to dissolve the insoluble purple formazan product into a colored solution. The absorbance of the wells was quantified by measuring the optical density at 540 nm. Results were expressed as percentage of control cell growth. The IC50 values (concentration of drug that produces a 50% inhibition of cell growth) used for the combination studies were calculated using Prism v5.02 software (GraphPad). The results were expressed as molar concentration and represented the average of 2-4 independent assays.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the A549 tumor cell line are shown in table 1.

TABLE 1 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 3.60E−09 Oxaliplatin 9.00E−04 5-FU 9.23E−05 Gemcitabine 2.80E−10 Paclitaxel 4.00E−08 Docetaxel 3.00E−09 Vincristine 2.50E−07 Daunorubicin 3.55E−07 Mitomycin C 2.49E−04 Actinomycin D 4.70E−09 Topotecan 8.00E−07 Etoposide 7.82E−07 Bortezomib 3.10E−09 Vorinostat 6.81E−06 Cyclophosphamide 1.00E−03 Carmustine 1.00E−03 Dacarbazine 6.00E−04 Temsirolimus 3.29E−06 Erlotinib 1.00E−05 ET-743 2.25E−08 PM00104 7.00E−09

-   -   b. In a second set of assays, A549 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above. The previously obtained IC₅₀ values were used         as starting concentrations for each compound (100%         concentration). Arbitrary dilutions, as percentage of the         initial IC₅₀ value (100%, 75%, 70%, 60%, 50%, 40%, 30%, 25%, and         0%), were performed for each pair of compounds and tested in         combined complementary (opposite concentrations) dose-response         curves as follows:

IC₅₀ of PM01183 IC₅₀ of Agent 100%  0%  75% 25%  70% 30%  60% 40%  50% 50%  40% 60%  30% 70%  25% 75%   0% 100% 

As a visual aid, response values were plotted on a scatter plot with dose ratios given on the x-axis and % response values on the y-axis. A horizontal line was drawn between the two endpoint response values (E.g. between the response values for 100% IC₅₀ PM01183 and 100% IC₅₀ standard chemotherapeutic agent). In cases where response values at the two endpoints were approximately equivalent, points lying above or below this predicted line of additivity could be interpreted as representing antagonistic or synergistic drug interaction, respectively.

The in vitro combinations of each drug with PM01183 have the potential to be synergistic, additive or antagonistic. Synergistic cytotoxicity to tumor cells is an optimal effect and implies that the combination of PM01183 with another drug is more effective than either drug alone.

According to this assay, it was found that in A549 human lung carcinoma cell line:

-   -   a. The combination of PM01183 with oxaliplatin exhibited strong         synergism (FIG. 1 ).     -   b. The combination of PM0183 with 5-fluorouracil (FIG. 2 ) and         PM01183 with gemcitabine (FIG. 3 ) showed synergism at almost         all dose ratios.     -   c. The combination of PM01183 with paclitaxel showed synergism         (FIG. 4 ) at the dose ratios, while the combination of PM01183         with docetaxel showed synergism (FIG. 5 ) at the 75/25 and 50/50         dose ratios, and the combination of PM01183 with vincristine         exhibited synergism (FIG. 6 ) at almost all dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 7 ),         PM01183 with mitomycin C (FIG. 8 ), and PM01183 with actinomycin         D (FIG. 9 ) exhibited synergism at almost all dose ratios.     -   e. The combination of PM01183 with topotecan showed strong         synergism (FIG. 10 ), while the combination of PM01183 with         etoposide showed synergism (FIG. 11 ) at the and 25/75 dose         ratios.     -   f. The combination of PM01183 with bortezomib showed synergism         (FIG. 12 ) at the dose ratios.     -   g. The combination of PM01183 with vorinostat (FIG. 13 ) showed         strong synergism at almost all dose ratios.     -   h. The combination of PM01183 with cyclophosphamide (FIG. 14 )         showed synergism at almost all dose ratios.     -   i. The combination of PM01183 with carmustine exhibited strong         synergism (Figure     -   j. The combination of PM01183 with dacarbazine showed strong         synergism (FIG. 16 ).     -   k. The combinations of PM01183 with temsirolimus showed         synergism (FIG. 17 ) at almost all dose ratios.     -   l. The combination of PM01183 with erlotinib showed strong         synergism (FIG. 18 ).     -   m. The combination of PM01183 with ET-743 showed synergism (FIG.         19 ) at the and 30/70 dose ratios.     -   n. The combination of PM01183 with PM00104 (FIG. 20 ) showed         synergism at almost all dose ratios.

Example 2. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Sarcoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of sarcoma.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, cyclophosphamide, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), gemcitabine, docetaxel, vincristine, vinorelbine, daunorubicin, cytarabine, actinomycin D, topotecan, etoposide, vorinostat, dacarbazine, temsirolimus, erlotinib, aplidine, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

A673 was the human rhabdomyosarcoma cell line selected for this assay. A673 cells were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the A673 tumor cell         line.

The IC50 values (72 hours drug exposure) of each individual agent for the A673 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 2.

TABLE 2 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 2.20E−09 Cisplatin  3.03−05 Oxaliplatin 7.80E−05 Cytarabine 1.97E−07 Gemcitabine 4.34E−10 Docetaxel 6.50E−10 Vincristine 8.60E−09 Vinorelbine 5.00E−08 Daunorubicin 5.20E−07 Mitomycin C 2.99E−06 Actinomycin D 9.56E−10 Topotecan 2.40E−08 Etoposide 1.55E−06 Vorinostat 2.16E−06 Cyclophosphamide 1.00E−03 Dacarbazine 3.00E−04 Temsirolimus 1.00E−06 Erlotinib 5.00E−05 Aplidine 2.16E−09 ET-743 1.90E−09 PM02734 3.60E−06 PM00104 3.00E−09

-   -   b. In a second set of assays, A673 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in example 1.

According to this assay, it was found that in A673 human sarcoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 21 ) and         PM01183 with oxaliplatin (FIG. 22 ) exhibited strong synergism.     -   b. The combination of PM01183 with cytarabine exhibited strong         synergism (FIG. 23 ), while the combination of PM01183 with         gemcitabine showed synergism (FIG. 24 ) at the 75/25-70/30 dose         ratios.     -   c. The combination of PM01183 with docetaxel (FIG. 25 ), PM01183         with vincristine (FIG. 26 ) and PM01183 with vinorelbine (FIG.         27 ) showed synergism at almost all dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 28 ) and         PM01183 with actinomycin D (FIG. 30 ) showed synergism at almost         all dose ratios, while the combination of PM01183 with mitomycin         C (FIG. 29 ) exhibited strong synergism.     -   e. The combination of PM01183 with topotecan (FIG. 31 ) and         PM01183 with etoposide (FIG. 32 ) exhibited strong synergism at         almost all dose ratios.     -   f. The combination of PM01183 with vorinostat (FIG. 33 ) showed         strong synergism.     -   g. The combination of PM01183 with cyclophosphamide (FIG. 34 )         showed synergism at almost all dose ratios.     -   h. The combination of PM01183 with dacarbazine showed synergism         (FIG. 35 ) at the and 40/60 dose ratios.     -   i. The combinations of PM01183 with temsirolimus showed strong         synergism (FIG. 36 ).     -   j. The combination of PM01183 with erlotinib exhibited strong         synergism (FIG. 37 ).     -   k. The combination of PM01183 with aplidine showed synergism         (FIG. 38 ) at the dose ratios.     -   l. The combination of PM01183 with ET-743 (FIG. 39 ) showed         synergism at the dose ratios.     -   m. The combination of PM01183 with PM02734 (FIG. 40 ) showed         synergism at the 75/25 and 40/60 dose ratios.     -   n. The combination of PM01183 with PM00104 exhibited synergism         (FIG. 41 ).

Example 3. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Malignant Melanoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of malignant melanoma.

The following agents were evaluated in combination with PM01183: cisplatin, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, doxorubicin, daunorubicin, cytarabine, topotecan, irinotecan, methotrexate, etoposide, dacarbazine, temsirolimus, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

SK-MEL-2 was the human melanoma cell line selected for this assay. SK-MEL-2 cells were maintained in Minimum Essential Medium Eagle (MEME) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the SK-MEL-2 tumor         cell line.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the SK-MEL-2 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 3.

TABLE 3 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 2.00E−09 Cisplatin 1.60E−04 5-FU 7.00E−04 Cytarabine 3.89E−06 Methotrexate 1.00E−04 Daunorubicin 1.77E−07 Doxorubicin 3.00E−07 Mitomycin C 9.00E−07 Topotecan 4.37E−07 Irinotecan 1.80E−05 Etoposide 2.89E−06 Dacarbazine 6.30E−04 Temsirolimus 5.00E−05 ET-743 2.00E−09 PM02734 1.76E−06 PM00104 2.00E−09

-   -   b. In a second set of assays, SK-MEL-2 tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.

Cell culture and cell plating were performed as described before and the cytotoxic effect was measured by the MTT Assay as disclosed in example 1.

According to this assay, it was found that in SK-MEL-2 human melanoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 42 ) showed         synergism at the 75/25, 50/50 and 30/70 dose ratios.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 43 ),         PM01183 with cytarabine (FIG. 44 ), and PM01183 with         methotrexate (FIG. 45 ) exhibited strong synergism.     -   c. The combination of PM01183 with daunorubicin (FIG. 46 ) and         PM01183 with doxorubicin (FIG. 47 ) showed synergism at almost         all dose ratios, while the combination of PM01183 with mitomycin         C (FIG. 48 ) exhibited strong synergism.     -   d. The combination of PM01183 with topotecan (FIG. 49 ), PM01183         with irinotecan (FIG. 50 ), and PM01183 with etoposide (FIG. 51         ) exhibited synergism and even strong synergism in some dose         ratios.     -   e. The combination of PM01183 with dacarbazine showed synergism         (FIG. 52 ).     -   f. The combinations of PM01183 with temsirolimus showed strong         synergism (FIG. 53 ).     -   g. The combination of PM01183 with ET-743 (FIG. 54 ) showed         synergism at almost all dose ratios.     -   h. The combination of PM01183 with PM02734 (FIG. 55 ) showed         synergism at the dose ratios.     -   i. The combination of PM01183 with PM00104 (FIG. 56 ) exhibited         synergism at almost all dose ratios.

Example 4. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Prostate Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of prostate cancer.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, docetaxel, paclitaxel, vinorelbine, daunorubicin, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, methotrexate, etoposide, vorinostat, temsirolimus, bortezomib, erlotinib, flutamide, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

PC-3 was the human prostate adenocarcinome cell line selected for this assay. PC-3 cells were maintained in Roswell Park Memorial Institute medium (RPMI) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the PC-3 tumor cell         line.         The IC₅₀ values (72 hours drug exposure) of each individual         agent for the PC-3 tumor cell line were calculated by using the         same methodology disclosed in example 1 and are shown in table         4.

TABLE 4 IC₅₀ values in molar concentration (M) for each of the agent Com- Com- pound IC₅₀ (M) pound IC₅₀ (M) Compound IC₅₀ (M) PM01183 2.60E−09 Cisplatin 1.10E−04 Oxaliplatin 1.71E−04 5-FU 1.00E−03 Cytarabine 4.00E−05 Gemcita- 4.00E−07 bine Metho- 1.20E−04 Docetaxel 1.86E−08 Paclitaxel 9.00E−08 trexate Vinorel- 1.00E−05 Dauno- 1.15E−06 Doxo- 1.48E−06 bine rubicin rubicin Mitomycin 1.00E−05 Actino- 1.00E−08 Topotecan 6.33E−07 C mycin D Irinotecan 7.00E−05 Etoposide 4.80E−05 Bortezomib 8.00E−07 Vorinostat 3.90E−06 Flutamide 4.90E−05 Temsiroli- 5.00E−07 mus Erlotinib 2.33E−04 ET-743 8.00E−09 PM02734 5.40E−07 PM00104 7.10E−09

-   -   b. In a second set of assays, PC-3 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in examples 1.

According to this assay it was found that in PC-3 human prostate cancer cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 57 ) showed         synergism at almost all dose ratios, while the combination of         PM01183 with oxaliplatin (FIG. 58 ) exhibited strong synergism.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 59 ) and         PM01183 with cytarabine (FIG. 60 ) exhibited synergism at almost         all dose ratios, and the combination of PM01183 with gemcitabine         exhibited strong synergism (FIG. 61 ). Finally, the combination         of PM01183 with methotrexate showed synergism (FIG. 62 ) at the         30/70-25/75 dose ratios.     -   c. The combination of PM01183 with docetaxel showed synergism         (FIG. 63 ) at almost all dose ratios, while the combination of         PM01183 with paclitaxel (FIG. 64 ) showed synergism at the         40/60-30/70 dose ratios. The combination of PM01183 with         vinorelbine (FIG. 65 ) showed strong synergism.     -   d. The combination of PM01183 with daunorubicin (FIG. 66 ) and         PM01183 with doxorubicin (FIG. 67 ) exhibited strong synergism.         The combination of PM01183 with mitomycin C (FIG. 68 ) and         PM01183 with actinomycin D (FIG. 69 ) showed synergism at almost         all dose ratios.     -   e. The combination of PM01183 with topotecan (FIG. 70 ) and         PM01183 with irinotecan (FIG. 71 ) exhibited strong synergism,         while the combination of PM01183 with etoposide (FIG. 72 )         showed synergism at almost all dose ratios.     -   f. The combination of PM01183 with bortezomib (FIG. 73 ) showed         synergism at almost all dose ratios.     -   g. The combination of PM01183 with vorinostat (FIG. 74 ) showed         synergism.     -   h. The combination of PM01183 with flutamide (FIG. 75 ) showed         synergism at the dose ratios.     -   i. The combination of PM01183 with temsirolimus exhibited strong         synergism (FIG. 76 ).     -   j. The combination of PM01183 with erlotinib (FIG. 77 ) showed         synergism at almost all dose ratios.     -   k. The combination of PM01183 with ET-743 (FIG. 78 ) showed         synergism at almost all dose ratios.     -   l. The combination of PM01183 with PM02734 (FIG. 79 ) showed         synergism at the 75/25-70/30 and 30/70 dose ratios.     -   m. The combination of PM01183 with PM00104 exhibited strong         synergism (FIG. 80 ).

Example 5. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Pancreas Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of pancreatic carcinoma.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), gemcitabine, daunorubicin, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, methotrexate, etoposide, vorinostat, temsirolimus, bortezomib, erlotinib, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

PANC-1 was the human pancreatic carcinoma cell line selected for this assay. PANC-1 cells were maintained in Roswell Park Memorial Institute medium (RPMI) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the PANG-1 tumor         cell line.         The IC₅₀ values (72 hours drug exposure) of each individual         agent for the PANG-1 tumor cell line were calculated by using         the same methodology disclosed in example 1 and are shown in         table 5.

TABLE 5 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 2.80E−09 Cisplatin 1.47E−04 Oxaliplatin 1.84E−04 Cytarabine 9.00E−05 Gemcita- 1.00E−06 Methotrexate 1.00E−05 bine Dauno- 8.69E−07 Doxo- 3.45E−06 Actinomycin 2.20E−08 rubicin rubicin D Topotecan 4.37E−06 Irinotecan 9.00E−05 Etoposide 1.00E−05 Bortezomib 4.16E−07 Vorinostat 6.05E−06 Temsirolimus 1.00E−05 Erlotinib 4.16E−07 ET-743 2.10E−08 PM02734 9.00E−06 PM00104 7.89E−09

-   -   b. In a second set of assays, PANG-1 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed example 1.

According to this assay it was found that in PANG-1 human pancreas carcinoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 81 ) and         PM01183 with oxaliplatin (FIG. 82 ) exhibited strong synergism.     -   b. The combination of PM01183 with cytarabine (FIG. 83 ) showed         synergism at almost all dose ratios, while the combination of         PM01183 with gemcitabine (FIG. 84 ) and PM01183 with         methotrexate (FIG. 85 ) exhibited strong synergism.     -   c. The combination of PM01183 with daunorubicin (FIG. 86 ) and         PM01183 with doxorubicin (FIG. 87 ) exhibited synergism, while         the combination of PM01183 with actinomycin D (FIG. 88 ) showed         synergism at the 75/25 and 30/70-25/75 dose ratios.     -   d. The combination of PM01183 with topotecan (FIG. 89 ) and         PM01183 with irinotecan (FIG. 90 ) exhibited strong synergism,         while the combination of PM01183 with etoposide (FIG. 91 )         showed synergism at almost all dose ratios.     -   e. The combination of PM01183 with bortezomib (FIG. 92 ) showed         synergism at the 75/25-70/30 and 50/50 dose ratios.     -   f. The combination of PM01183 with vorinostat (FIG. 93 ) showed         synergism at almost all dose ratios.     -   g. The combination of PM01183 with temsirolimus exhibited strong         synergism (FIG. 94 ).     -   h. The combination of PM01183 with erlotinib exhibited strong         synergism (FIG. 95 ).     -   i. The combination of PM01183 with ET-743 (FIG. 96 ) showed         synergism at almost all dose ratios.     -   j. The combination of PM01183 with PM02734 (FIG. 97 ) showed         synergism at almost all dose ratios.     -   k. The combination of PM01183 with PM00104 showed synergism         (FIG. 98 ) at the and 50/50 dose ratios.

Example 6. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Gastric Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of gastric cancer.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, cyclophosphamide (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, paclitaxel, vincristine, vinorelbine, daunorubicin, dacarbazine, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, methotrexate, etoposide, vorinostat, temsirolimus, bortezomib, erlotinib, aplidine, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

HGC-27 was the human gastric carcinoma cell line selected for this assay. HGC-27 cells were maintained in Iscove's modified Dulbeco's medium (IDMD) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the HGC-27 tumor         cell line.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the HGC-27 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 6.

TABLE 6 IC₅₀ values in molar concentration (M) for each of the agent IC₅₀ IC₅₀ IC₅₀ Compound (M) Compound (M) Compound (M) PM01183 8.50E−10 Cisplatin 8.00E−05 Oxaliplatin 1.06E−04 5-FU 1.00E−05 Cytarabine 5.00E−05 Gemcitabine 5.34E−10 Metho- 3.30E−08 Paclitaxel 5.00E−09 Vincristine 1.25E−08 trexate Vinorel- 6.50E−08 Dauno- 3.72E−07 Doxorubicin 5.40E−08 bine rubicin Actino- 3.74E−09 Topotecan 8.08E−07 Irinotecan 4.00E−06 mycin D Etoposide 2.90E−06 Bortezomib 5.60E−09 Vorinostat 1.20E−06 Cyclophos- 1.00E−03 Dacarbazine 3.46E−04 Temsirolimus 1.50E−07 phamide Erlotinib 7.50E−06 Aplidine 9.00E−09 ET-743 5.80E−09 PM02734 9.50E−07 PM00104 3.20E−09

-   -   b. In a second set of assays, HGC-27 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed, as described         before and the cytotoxic effect was measured by the MTT Assay,         as disclosed in example 1.

According to this assay it was found that in HGC-27 human gastric carcinoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 99 ) showed         synergism at almost all dose ratios, while the combination of         PM01183 with oxaliplatin (FIG. 100 ) exhibited strong synergism.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 101 )         and PM01183 with cytarabine (FIG. 102 ) exhibited synergism,         even being strong in some dose ratios. The combination of         PM01183 with gemcitabine (FIG. 103 ) and PM01183 with         methotrexate (FIG. 104 ) showed synergism at almost all dose         ratios.     -   c. The combination of PM01183 with paclitaxel exhibited strong         synergism (FIG. 105 ). The combination of PM01183 with         vincristine (FIG. 106 ) and PM01183 with vinorelbine (FIG. 107 )         showed synergism at almost all dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 108 ) and         PM01183 with actinomycin D (FIG. 110 ) exhibited strong         synergism. The combination of PM01183 with doxorubicin (FIG. 109         ) exhibited synergism at the 75/25-60/40 dose ratios.     -   e. The combination of PM01183 with topotecan exhibited strong         synergism (FIG. 111 ). The combination of PM01183 with         irinotecan (FIG. 112 ) showed synergism at the 70/30-60/40 and         40/60 dose ratios, while the combination of PM01183 with         etoposide (FIG. 113 ) showed synergism at almost all dose         ratios.     -   f. The combination of PM01183 with bortezomib exhibited strong         synergism (FIG. 114 ).     -   g. The combination of PM01183 with vorinostat (FIG. 115 ) showed         synergism at almost all dose ratios.     -   h. The combination of PM01183 with cyclophosphamide exhibited         strong synergism (FIG. 116 ).     -   i. The combination of PM01183 with dacarbazine exhibited strong         synergism (FIG. 117 ).     -   j. The combination of PM01183 with temsirolimus exhibited strong         synergism (FIG. 118 ).     -   k. The combination of PM01183 with erlotinib exhibited strong         synergism (FIG. 119 ).     -   l. The combination of PM01183 with aplidine showed strong         synergism (FIG. 120 ).     -   m. The combination of PM01183 with ET-743 (FIG. 121 ) showed         synergism at the and 75/25 dose ratios.     -   n. The combination of PM01183 with PM02734 exhibited strong         synergism (FIG. 122 ).     -   o. The combination of PM01183 with PM00104 (FIG. 123 ) showed         synergism at almost all dose ratios.

Example 7. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Ovarian Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of ovarian cancer.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, cyclophosphamide, carmustine, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, docetaxel, paclitaxel, vincristine, vinorelbine, daunorubicin, dacarbazine, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, methotrexate, etoposide, vorinostat, temsirolimus, erlotinib, aplidine, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

IGROV-1 was the human ovarian adenocarcinoma cell line selected for this assay. IGROV-1 cells were maintained in Roswell Park Memorial Institute medium (RPMI) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the IGROV-1 tumor         cell line.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the IGROV-1 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 7.

TABLE 7 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 3.20E−09 Cisplatin 7.00E−05 Oxaliplatin 8.50E−06 5-FU 9.00E−05 Cytarabine 1.17E−05 Gemcitabine 6.34E−09 Methotrexate 1.00E−04 Docetaxel 5.01E−08 Paclitaxel 9.50E−08 Vincristine 3.79E−07 Vinorelbine 1.39E−06 Daunorubicin 3.55E−07 Doxorubicin 2.59E−07 Actinomycin D 3.29E−09 Mitomycin C 3.00E−06 Topotecan 3.00E−07 Irinotecan 1.00E−05 Etoposide 3.06E−06 Vorinostat 2.88E−06 Carmustine 7.12E−04 Cyclophosphamide 1.00E−03 Dacarbazine 3.98E−04 Temsirolimus 1.27E−07 Erlotinib 7.91E−06 Aplidine 1.50E−09 ET-743 6.45E−09 PM02734 3.33E−07 PM00104 3.30E−09

-   -   b. In a second set of assays, IGROV-1 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in example 1.

According to this assay it was found that in IGROV-1 human ovarian carcinoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 124 ) showed         synergism at almost all dose ratios, while the combination of         PM01183 with oxaliplatin exhibited strong synergism (FIG. 125 ).     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 126 )         and PM01183 with cytarabine (FIG. 127 ) showed synergism at         almost all dose ratios. The combination of PM01183 with         gemcitabine (FIG. 128 ) and PM01183 with methotrexate (FIG. 129         ) exhibited synergism.     -   c. The combination of PM01183 with docetaxel (FIG. 130 ),         PM01183 with paclitaxel (FIG. 131 ), and PM01183 with         vincristine (FIG. 132 ) exhibited strong synergism, while the         combination of PM01183 with vinorelbine (FIG. 133 ) showed         synergism at almost all dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 134 )         exhibited synergism. The combination of PM01183 with doxorubicin         (FIG. 135 ) and PM01183 with actinomycin D (FIG. 136 ) exhibited         synergism at almost all dose ratios, while the combination of         PM01183 with mitomycin C (FIG. 137 ) showed synergism at the and         30/70-25/75 dose ratios.     -   e. The combination of PM01183 with topotecan (FIG. 138 ),         PM01183 with irinotecan (FIG. 139 ), and PM01183 with etoposide         (FIG. 140 ) exhibited synergism.     -   f. The combination of PM01183 with vorinostat (FIG. 141 ) showed         synergism at almost all dose ratios.     -   g. The combination of PM01183 with cyclophosphamide (FIG. 142 )         showed synergism at almost all dose ratios.     -   h. The combination of PM01183 with carmustine (FIG. 143 )         exhibited synergism at almost all dose ratios.     -   i. The combination of PM01183 with dacarbazine (FIG. 144 )         showed synergism at almost all dose ratios.     -   j. The combination of PM01183 with temsirolimus exhibited         synergism (FIG. 145 ).     -   k. The combination of PM01183 with erlotinib exhibited synergism         (FIG. 146 ).     -   l. The combination of PM01183 with aplidine (FIG. 147 ) showed         synergism at the dose ratios.     -   m. The combination of PM01183 with ET-743 (FIG. 148 ) showed         synergism at the dose ratios.     -   n. The combination of PM01183 with PM02734 exhibited strong         synergism (FIG. 149 ).     -   o. The combination of PM01183 with PM00104 (FIG. 150 ) showed         synergism at almost all dose ratios.

Example 8. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Hepatocellular Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of hepatocellular cancer.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, cyclophosphamide (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, paclitaxel, docetaxel, vincristine, vinorelbine, daunorubicin, cytarabine, doxorubicin, topotecan, irinotecan, methotrexate, etoposide, bortezomib, erlotinib, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

HepG2 was the human hepatocellular liver carcinoma cell line selected for this assay. HepG2 cells were maintained in Minimum Essential Medium Eagle (MEME) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the HepG2 tumor         cell line.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the HepG2 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 8.

TABLE 8 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 2.50E−09 Cisplatin 5.00E−05 Oxaliplatin 2.80E−05 5-FU 4.50E−06 Cytarabine 2.06E−05 Gemcitabine 5.34E−09 Metho- 3.96E−08 Docetaxel 5.00E−07 Paclitaxel 5.70E−08 trexate Vincristine 6.00E−08 Vinorelbine 1.02E−06 Daunorubicin 3.00E−07 Doxo- 2.00E−07 Topotecan 1.00E−06 Irinotecan 1.00E−06 rubicin Etoposide 1.04E−05 Bortezomib 3.90E−07 Cyclo- 1.00E−03 phosphamide Erlotinib 8.60E−06 ET-743 7.21E−09 PM00104 3.00E−09

-   -   b. In a second set of assays, HepG2 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in example 1.

According to this assay it was found that in HepG2 human hepatocellular cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 151 ) and         PM01183 with oxaliplatin (FIG. 152 ) exhibited strong synergism.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 153 )         showed synergism at the 75/25, 50/50 and 30/70 dose ratios. The         combination of PM01183 with cytarabine (FIG. 154 ), PM01183 with         gemcitabine (FIG. 155 ) and PM01183 with methotrexate (FIG. 156         ) exhibited strong synergism.     -   c. The combination of PM01183 with docetaxel (FIG. 157 )         exhibited strong synergism. The combination of PM01183 with         paclitaxel (FIG. 158 ) and PM01183 with vincristine (FIG. 159 )         showed synergism at almost all dose ratios, while the         combination of PM01183 with vinorelbine (FIG. 160 ) showed         synergism at the 50/50 and 30/70-25/75 dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 161 ) and         PM01183 with doxorubicin (FIG. 162 ) showed synergism at almost         all dose ratios.     -   e. The combination of PM01183 with topotecan (FIG. 163 ) and         PM01183 with etoposide (FIG. 165 ) exhibited strong synergism.         The combination of PM01183 with irinotecan (FIG. 164 ) showed         synergism at almost all dose ratios.     -   f. The combination of PM01183 with bortezomib (FIG. 166 ) showed         synergism at the dose ratios.     -   g. The combination of PM01183 with cyclophosphamide (FIG. 167 )         showed synergism at almost all dose ratios.     -   h. The combination of PM01183 with erlotinib (FIG. 168 )         exhibited strong synergism.     -   i. The combination of PM01183 with ET-743 (FIG. 169 ) showed         synergism at the dose ratios.     -   j. The combination of PM01183 with PM00104 (FIG. 170 ) exhibited         strong synergism.

Example 9. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Breast Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of breast cancer.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, cyclophosphamide, carmustine, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, paclitaxel, docetaxel, vincristine, vinorelbine, daunorubicin, dacarbazine, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, methotrexate, etoposide, vorinostat, temsirolimus, erlotinib, tamoxifen, PM02734, ET-743 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

MDA-MB-231 was the human breast adenocarcinoma cell line selected for this assay. MDA-MB-231 cells were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the MDA-MB-231         tumor cell line.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the MDA-MB-231 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 9.

TABLE 9 IC₅₀ values in molar concentration (M) for each of the agent Com- pound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 3.50E−09 Cisplatin 1.53E−04 Oxaliplatin 1.08E−04 5-FU 9.00E−05 Cytarabine 9.57E−06 Gemcitabine 8.50E−09 Metho- 5.94E−06 Docetaxel 2.50E−09 Paclitaxel 8.50E−09 trexate Vincristine 5.00E−08 Vinorelbine 1.20E−05 Dauno- 3.70E−07 rubicin Doxo- 6.00E−07 Actino- 4.54E−10 Mito- 2.00E−06 rubicin mycin mycin D C Topotecan 1.66E−07 Irinotecan 8.50E−06 Etoposide 4.80E−06 Vorinostat 1.70E−06 Cyclo- 1.00E−03 Carmustine 9.00E−04 phos- phamide Dacarba- 1.92E−05 Tamoxifen 1.30E−05 Temsiroli- 1.20E−05 zine mus Erlotinib 1.00E−04 ET-743 2.00E−09 PM02734 2.80E−06 PM00104 1.00E−09

-   -   b. In a second set of assays, MDA-MB-231 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in example 1.

According to this assay it was found that in MDA-MB-231 human breast carcinoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 171 ) and         PM01183 with oxaliplatin (FIG. 172 ) exhibited synergism.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 173 )         showed synergism at almost all dose ratios. The combination of         PM01183 with cytarabine (FIG. 174 ) and PM01183 with gemcitabine         (FIG. 175 ) exhibited strong synergism, while the combination of         PM01183 with methotrexate (FIG. 176 ) showed synergism at the         and 50/50 dose ratios.     -   c. The combination of PM01183 with docetaxel (FIG. 177 ) and         PM01183 with paclitaxel (FIG. 178 ) exhibited synergism. The         combination of PM01183 with vincristine (FIG. 179 ) showed         synergism at the 75/25 and 50/50 dose ratios, while the         combination of PM01183 with vinorelbine (FIG. 180 ) showed         synergism at almost all dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 181 ) and         PM01183 with mitomycin C (FIG. 184 ) exhibited synergism at         almost all dose ratios. The combination of PM01183 with         doxorubicin (FIG. 182 ) exhibited strong synergism and the         combination of PM01183 with actinomycin D (FIG. 183 ) exhibited         synergism.     -   e. The combination of PM01183 with topotecan (FIG. 185 ) showed         synergism at almost all dose ratios. The combination of PM01183         with irinotecan (FIG. 186 ) and PM01183 with etoposide (FIG. 187         ) exhibited synergism.     -   f. The combination of PM01183 with vorinostat (FIG. 188 ) showed         synergism at 75/25 and 50/50-40/60 dose ratios.     -   g. The combination of PM01183 with cyclophosphamide (FIG. 189 )         exhibited strong synergism.     -   h. The combination of PM01183 with carmustine (FIG. 190 )         exhibited synergism at almost all dose ratios.     -   i. The combination of PM01183 with dacarbazine (FIG. 191 )         showed synergism at almost all dose ratios.     -   j. The combination of PM01183 with tamoxifen (FIG. 192 ) showed         synergism at almost all dose ratios     -   k. The combination of PM01183 with temsirolimus exhibited strong         synergism (FIG. 193 ).     -   l. The combination of PM01183 with erlotinib exhibited strong         synergism (FIG. 194 ).     -   m. The combination of PM01183 with ET-743 exhibited strong         synergism (FIG. 195 ).     -   n. The combination of PM01183 with PM02734 (FIG. 196 ) exhibited         synergism at almost all dose ratios.     -   o. The combination of PM01183 with PM00104 (FIG. 197 ) showed         synergism at almost all dose ratios.

Example 10. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Colorectal Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of colorectal cancer.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin, cyclophosphamide, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, docetaxel, vinorelbine, daunorubicin, dacarbazine, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, etoposide, vorinostat, bortezomib, temsirolimus, erlotinib, PM02734 and aplidine (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

HT-29 was the human colon adenocarcinoma cell line selected for this assay. HT-29 cells were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the HT-29 tumor         cell line.

The IC50 values (72 hours drug exposure) of each individual agent for the HT-29 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 10.

TABLE 10 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 3.70E−09 Cisplatin 2.20E−04 Oxaliplatin 1.03E−04 5-FU 9.00E−06 Cytarabine 7.80E−06 Gemcitabine 4.00E−07 Docetaxel 3.20E−10 Vinorelbine 3.00E−08 Daunorubicin 5.32E−07 Doxorubicin 9.00E−07 Actinomycin D 3.27E−09 Mitomycin C 2.00E−06 Topotecan 3.28E−07 Irinotecan 9.00E−06 Etoposide 5.44E−06 Bortezomib 6.15E−09 Vorinostat 2.76E−06 Cyclophosphamide 1.00E−03 Dacarbazine 2.47E−05 Temsirolimus 3.50E−06 Erlotinib 2.56E−05 Aplidine 1.76E−09 PM02734 2.14E−07

-   -   b. In a second set of assays, HT-29 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in example 1.

According to this assay it was found that in HT-29 human colorectal carcinoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 198 ) showed         synergism at the dose ratios, while the combination of PM01183         with oxaliplatin (FIG. 199 ) exhibited strong synergism.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 200 )         and PM01183 with gemcitabine (FIG. 202 ) showed synergism at         almost all dose ratios, and the combination of PM01183 with         cytarabine (FIG. 201 ) exhibited strong synergism.     -   c. The combination of PM01183 with docetaxel (FIG. 203 )         exhibited synergism at the and 75/25 dose ratios, while the         combination of PM01183 with vinorelbine (FIG. 204 ) showed         synergism at almost all dose ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 205 ) and         PM01183 with mitomycin C (FIG. 208 ) exhibited strong synergism.         The combination of PM01183 with doxorubicin (FIG. 206 ) and         PM01183 with actinomycin D (FIG. 207 ) showed synergism at         almost all dose ratios.     -   e. The combination of PM01183 with topotecan (FIG. 209 ) and         PM01183 with etoposide (FIG. 211 ) exhibited strong synergism.         The combination of PM01183 with irinotecan (FIG. 210 ) showed         synergism at almost all dose ratios.     -   f. The combination of PM01183 with bortezomib (FIG. 212 ) showed         synergism at almost all dose ratios.     -   g. The combination of PM01183 with vorinostat (FIG. 213 )         exhibited synergism.     -   h. The combination of PM01183 with cyclophosphamide (FIG. 214 )         showed synergism at the 40/60-25/75 dose ratios.     -   i. The combination of PM01183 with dacarbazine (FIG. 215 )         exhibited strong synergism.     -   j. The combination of PM01183 with temsirolimus exhibited strong         synergism (FIG. 216 ).     -   k. The combination of PM01183 with erlotinib showed synergism at         almost all dose ratios (FIG. 217 ).     -   l. The combination of PM01183 with aplidine (FIG. 218 ) showed         synergism at the 40/60-25/75 dose ratios.     -   m. The combination of PM01183 with PM02734 (FIG. 219 ) showed         synergism at almost all dose ratios.

Example 11. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Kidney Carcinoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of kidney cancer.

The following agents were evaluated in combination with PM01183: cisplatin, cyclophosphamide, mytomicin C (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, methotrexate, docetaxel, vincristine, vinorelbine, daunorubicin, dacarbazine, cytarabine, doxorubicin, actinomycin D, topotecan, irinotecan, etoposide, vorinostat, erlotinib, PM02734, ET-743, PM00104 and aplidine (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

RXF-393 was the human kidney carcinoma cell line selected for this assay. RXF-393 cells were maintained in Roswell Park Memorial Institute medium (RPMI) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the RXF-393 tumor         cell line.

The IC₅₀ values (72 hours drug exposure) of each individual agent for the RXF-393 tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 11.

TABLE 11 IC₅₀ values in molar concentration (M) for each of the agent Compound IC₅₀ (M) Compound IC₅₀ (M) Compound IC₅₀ (M) PM01183 5.00E−09 Cisplatin 6.67E−05 5-FU 3.00E−04 Cytarabine 5.00E−05 Gemcitabine 5.00E−07 Metho- 1.75E−04 trexate Docetaxel 5.94E−10 Vincristine 1.73E−08 Vinorel- 8.50E−06 bine Dauno- 6.20E−07 Doxorubicin 8.00E−07 Actino- 7.09E−10 rubicin mycin D Mitomycin 9.00E−06 Topotecan 3.93E−07 Irinotecan 1.40E−05 C Etoposide 2.00E−05 Vorinostat 4.10E−06 Cyclo- 1.00E−03 phos- phamide Dacarbazine 7.94E−04 Erlotinib 4.80E−06 Aplidine 1.50E−09 ET-743 9.60E−09 PM02734 5.00E−06 PM00104 5.40E−09

-   -   b. In a second set of assays, RXF-393 human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was measured by the MTT Assay as         disclosed in example 1.

According to this assay it was found that in RXF-393 human kidney carcinoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 220 ) showed         synergism at almost all dose ratios.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 221 ),         PM01183 with cytarabine (FIG. 222 ), PM01183 with gemcitabine         (FIG. 223 ), and PM01183 with methotrexate (FIG. 224 ) showed         synergism at almost all dose ratios.     -   c. The combination of PM01183 with docetaxel (FIG. 225 ),         PM01183 with vincristine (FIG. 226 ) and PM01183 with         vinorelbine (FIG. 227 ) showed synergism at almost all dose         ratios.     -   d. The combination of PM01183 with daunorubicin (FIG. 228 )         showed synergism at almost all dose ratios. The combination of         PM01183 with doxorubicin (FIG. 229 ) showed synergism at the         75/25-60/40 dose ratios, while the combination of PM01183 with         actinomycin D (FIG. 230 ) showed synergism at the 75/25-70/30         and 30/70 dose ratios. The combination of PM01183 with mitomycin         C (FIG. 231 ) exhibited strong synergism.     -   e. The combination of PM01183 with topotecan (FIG. 232 )         exhibited strong synergism. The combination of PM01183 with         irinotecan (FIG. 233 ) showed synergism at almost all dose         ratios, while the combination of PM01183 with etoposide (FIG.         234 ) showed synergism at the 75/25 and 40/60-30/70 dose ratios.     -   f. The combination of PM01183 with vorinostat (FIG. 235 ) showed         synergism at almost all dose ratios.     -   g. The combination of PM01183 with cyclophosphamide (FIG. 236 )         showed synergism at the 75/25-70/30 and 25/75 dose ratios.     -   h. The combination of PM01183 with dacarbazine (FIG. 237 )         showed synergism at the 60/40-50/50 dose ratios.     -   i. The combination of PM01183 with erlotinib exhibited strong         synergism (FIG. 238 ).     -   j. The combination of PM01183 with aplidine (FIG. 239 ) showed         synergism at almost all dose ratios.     -   k. The combination of PM01183 with ET-743 (FIG. 240 ) showed         synergism at almost all dose ratios.     -   l. The combination of PM01183 with PM02734 (FIG. 241 ) showed         synergism at almost all dose ratios.     -   m. The combination of PM01183 with PM00104 (FIG. 242 ) exhibited         strong synergism.

Example 12. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Glioblastoma Cell Lines

The objective of this study was to determine the ability of PM01183 to potentiate the antitumor activity of chemotherapeutic agents used in the treatment of glioblastoma.

The following agents were evaluated in combination with PM01183: cisplatin, oxaliplatin (stock solutions of these compounds prepared in sterile double distilled water and stored at −20° C.), 5-fluorouracil, gemcitabine, docetaxel, vincristine, daunorubicin, dacarbazine, doxorubicin, topotecan, irinotecan, methotrexate, etoposide, vorinostat, temsirolimus, bortezomib erlotinib, PM02734, ET-743 and aplidine (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

U87-MG was the human glioblastoma cell line selected for this assay. U87-MG cells were maintained in Minimum Essential Medium Eagle (MEME) supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts as disclosed in example 1:

-   -   a. In the first set of assays, IC₅₀ values were determined for         each drug after 72 hours of drug exposure in the U87-MG tumor         cell line.

The IC50 values (72 hours drug exposure) of each individual agent for the U87-MG tumor cell line were calculated by using the same methodology disclosed in example 1 and are shown in table 12.

TABLE 12 IC₅₀ values in molar concentration (M) for each of the agent Com- Compound IC₅₀ (M) Compound IC₅₀ (M) pound IC₅₀ (M) PM01183 4.50E−09 Cisplatin 4.40E−05 Oxalipla- 1.90E−04 tin 5-FU 1.00E−03 Gemcitabine 4.50E−07 Metho- 5.00E−05 trexate Docetaxel 1.00E−07 Vincristine 1.00E−07 Dauno- 2.84E−07 rubicin Doxorubicin 3.00E−07 Topotecan 7.50E−07 Irinotecan 7.54E−06 Etoposide 1.85E−05 Bortezomib 4.00E−07 Vorinostat 1.60E−05 Dacarbazine 7.00E−04 Temsirolimus 3.50E−06 Erlotinib 1.49E−04 Aplidine 3.80E−09 ET-743 5.00E−09 PM02734 4.08E−06

-   -   b. In a second set of assays, U87-MG human tumor cells were         incubated with PM01183 in combination with each of the agents         mentioned above in the same combination of unique IC₅₀         concentrations as those described in example 1.         Cell culture and cell plating were performed as described before         and the cytotoxic effect was also measured by the MTT Assay as         disclosed in example 1.

According to this assay it was found that in U87-MG human glioblastoma cell line:

-   -   a. The combination of PM01183 with cisplatin (FIG. 243 ) showed         synergism at the 70/30 and 50/50 dose ratios, while the         combination of PM01183 with oxaliplatin (FIG. 244 ) exhibited         strong synergism.     -   b. The combination of PM01183 with 5-fluorouracil (FIG. 245 )         and PM01183 with methotrexate (FIG. 247 ) exhibited synergism.         The combination of PM01183 with gemcitabine (FIG. 246 ) showed         synergism at almost all dose ratios.     -   c. The combination of PM01183 with docetaxel (FIG. 248 ) and         PM01183 with vincristine (FIG. 249 ) exhibited strong synergism.     -   d. The combination of PM01183 with daunorubicin (FIG. 250 )         showed synergism at almost all dose ratios, while the         combination of PM01183 with doxorubicin (FIG. 251 ) showed         synergism at the 75/25 and 60/40 dose ratios.     -   e. The combination of PM01183 with topotecan (FIG. 252 ) and         PM01183 with etoposide (FIG. 254 ) showed strong synergism. The         combination of PM01183 with irinotecan (FIG. 253 ) showed         synergism at almost all dose ratios.     -   f. The combination of PM01183 with bortezomib (FIG. 255 ) showed         synergism at almost all dose ratios.     -   g. The combination of PM01183 with vorinostat (FIG. 256 )         exhibited strong synergism.     -   h. The combination of PM01183 with dacarbazine (FIG. 257 )         exhibited synergism.     -   i. The combination of PM01183 with temsirolimus (FIG. 258 )         showed synergism at the 50/50 and 30/70 dose ratios.     -   j. The combination of PM01183 with erlotinib (FIG. 259 ) showed         synergism at the 40/60-25/75 dose ratios.     -   k. The combination of PM01183 with aplidine (FIG. 260 ) showed         synergism at the 50/50-25/75 dose ratios.     -   m. The combination of PM01183 with ET-743 (FIG. 261 ) exhibited         strong synergism.     -   l. The combination of PM01183 with PM02734 (FIG. 262 ) showed         strong synergism.

Example 13. In Vivo Studies to Determine the Effect of PM01183 in Combination with Paclitaxel, Vinorelbine and Doxorubicin in Human Ovarian Tumor Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of paclitaxel, vinorelbine and doxorubicin by using a xenograft model of human ovarian carcinoma.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was A2780 cell line, which was obtained from the European Collection of Cell Cultures (ECACC no 93112519).

A2780 cells were grown at 37° C. with 5% CO₂ in RPMI-1640 medium. Each animal was subcutaneously implanted on the right flank, using 26G needle and a 1 cc syringe, with 1×10⁷ A2780 cells (from in vitro passage 5 in PM01183 and doxorubicin and PM01183 and vinorelbine studies; and passage 9 in PM01183 and paclitaxel study), in 0.05 mL suspension of 50% Matrigel and 50% serum free medium, without antibiotics.

Tumor measurements were determined by using digital caliper (Fowler Sylvac, S235PAT). The formula to calculate volume for a prolate ellipsoid was used to estimate tumor volume (mm³) from 2-dimensional tumor measurements: Tumor volume (mm³)=[L×W²]÷2, where L is the length and it is the longest diameter in mm, and W is the width and it is the shortest diameter in mm of a tumor. Assuming unit density, volume was converted to weight (i.e., 1 mm³=1 mg). Tumor volume and animal body weights were measured 2-3 times per week starting form the first day of treatment (Day 0).

Treatment tolerability was assessed by monitoring body weight evolution, clinical signs as well as evidences of local damage in the injection site.

When tumors reached a volume of about 195 mm³ in the study of PM01183 with paclitaxel, a volume of about 158 mm³ in the study of PM01183 with vinorelbine and a volume of about 163.5 mm³ in the study of PM01183 with doxorubicin, the mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor volumen measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Doxorubicin was provided in the form of a solid powder containing Doxorubicin HCl, which was reconstituted in 0.9% saline solution. Vinorelbine was provided as a solution prepared by diluting the product with 0.9% saline solution. Paclitaxel was provided in the form of a solution prepared by diluting the product with 5% glucose solution for injection to the target final concentration.

In these experiments, PM01183 and paclitaxel, PM01183 and vinorelbine and PM01183 and doxorubicin treatments, as well as placebo, were intravenously administered once per week up to 2 consecutive weeks on Days 0 and 7. Dose level groups were administered either as single agents or in combination.

Comparison of the median tumor volume in the treatment groups (T) to the median tumor volume in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation was determined when the response of the combination group was greater than the best response of the most active agent administered as single agent (monotherapy) on the same schedule and dose as those used in the combination therapy.

Finally, the combination index (CI), that quantitatively measures the degree of drug interactions, was obtained from the fractions affected by the treatment, Fa (defined as 1−T/C) for each experimental group at the last measurement day (Day 10 for PM01183 and paclitaxel combination study, and PM01183 and doxorubicin study, and Day 9 for PM01183 and vinorelbine study) using the median-effect principle (Chou T. C. Pharmacol. Rev. 2006, 58, 621-681).

Table 13 reports the % T/C values obtained with PM01183 and paclitaxel both administered as single agents and in combination for each dose level, and FIG. 263 shows the tumor volume evaluation of A2780 tumors in mice treated with placebo, PM01183, paclitaxel, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 13 Test % T/C on day Group Dose materials 0 3 5 7 10 G01 10 ml/kg Placebo — — — — — (Control group) G02 0.18 mg/kg PM01183 101.6 68.9 83.1 69.1 52.8 G03 0.135 mg/kg PM01183 101.2 89.9 99.8 84.5 61.2 G04 0.09 mg/kg PM01183 94.2 88.5 114.1 103.3 88.0 G05 0.045 mg/kg PM01183 94.0 91.1 99.6 88.0 73.1 G06 25 mg/kg Paclitaxel 95.3 49.3 42.9 34.0 19.8 G07 18.75 mg/kg Paclitaxel 95.0 60.4 43.2 41.5 31.1 G08 12.5 mg/kg Paclitaxel 96.2 62.5 73.9 62.5 50.8 G09 6.25 mg/kg Paclitaxel 94.3 60.2 79.7 81.3 59.2 G10 0.18 mg/kg PM01183 93.3 45.9 28.8 20.9 9.2 25 mg/kg Paclitaxel G11 0.135 mg/kg PM01183 93.4 40.5 37.1 36.0 22.6 18.75 mg/kg Paclitaxel G12 0.09 mg/kg PM01183 96.5 64.3 67.7 73.2 49.0 12.5 mg/kg Paclitaxel G13 0.045 mg/kg PM01183 96.2 78.6 89.1 91.1 77.2 6.25 mg/kg Paclitaxel

Placebo: lyophilised cake containing 100 mg Sucrose+Potassium dihydrogen phosphate 6.8 mg+Phosphoric acid q.s. pH 3.8-4.5, which was reconstituted with 1 mL of water for infusion.

Table 14 reports the % T/C values obtained with PM01183 and vinorelbine both administered as single agents and in combination for each dose level, and FIG. 264 shows the tumor volume evaluation of A2780 tumors in mice treated with placebo, PM01183, vinorelbine, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 14 Test % T/C on day Group Dose materials 0 2 5 7 9 G01   10 ml/kg Placebo — — — — — (Control group) G02  0.18 mg/kg PM01183 98.9 101.6 72.2 61.3 62.8 G03 0.135 mg/kg PM01183 98.3 105.3 77.2 79.1 78.7 G04  0.09 mg/kg PM01183 98.0 88.6 61.2 87.6 94.5 G05 0.045 mg/kg PM01183 97.8 107.5 93.6 92.5 97.1 G06  16.0 mg/kg Vinorelbine 99.0 62.5 20.8 24.5 20.0 G07  12.0 mg/kg Vinorelbine 97.4 67.2 39.1 43.0 36.1 G08  8.0 mg/kg Vinorelbine 97.6 79.5 45.0 54.2 47.9 G09  4.0 mg/kg Vinorelbine 97.2 88.6 69.3 81.7 77.3 G10  0.18 mg/kg PM01183 97.3 50.1 10.9 10.6 8.6  16.0 mg/kg Vinorelbine G11 0.135 mg/kg PM01183 97.2 74.0 29.6 31.2 26.8  12.0 mg/kg Vinorelbine G12  0.09 mg/kg PM01183 96.8 69.3 48.3 56.5 49.8  8.0 mg/kg Vinorelbine G13 0.045 mg/kg PM01183 97.1 85.6 61.7 74.2 81.6  4.0 mg/kg Vinorelbine Placebo: as disclosed in table 13.

Table 15 reports the % T/C values obtained with PM01183 and doxorubicin both administered as single agents and in combination for each dose level, and FIG. 265 shows the tumor volume evaluation of A2780 tumors in mice treated with placebo, PM01183, doxorubicin, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 15 Test % T/C on day Group Dose materials 0 3 5 7 10 G01   10 ml/kg Placebo — — — — — (Control group) G02  0.18 mg/kg PM01183 100.9 70.2 68.5 69.3 62.1 G03 0.135 mg/kg PM01183 102.2 82.4 86.6 89.2 82.4 G04  0.09 mg/kg PM01183 100.2 93.3 95.2 93.5 87.7 G05 0.045 mg/kg PM01183 100.1 98.2 98.6 97.7 90.0 G06  8.0 mg/kg Doxorubicin 99.5 60.8 49.8 48.1 39.4 G07  6.0 mg/kg Doxorubicin 99.4 71.0 60.3 56.8 54.3 G08  4.0 mg/kg Doxorubicin 102.0 82.9 75.1 75.0 68.9 G09  2.0 mg/kg Doxorubicin 99.8 91.5 93.1 94.2 86.2 G10  0.18 mg/kg PM01183 99.7 47.6 32.6 30.3 21.1  8.0 mg/kg Doxorubicin G11 0.135 mg/kg PM01183 100.6 67.0 54.9 53.9 44.9  6.0 mg/kg Doxorubicin G12  0.09 mg/kg PM01183 98.3 74.7 69.0 63.1 64.4  4.0 mg/kg Doxorubicin G13 0.045 mg/kg PM01183 98.1 83.1 86.6 78.1 79.2  2.0 mg/kg Doxorubicin Placebo: as disclosed in table 13.

According to these assays it was found that:

-   -   a. The combination treatment of PM01183 and paclitaxel was         effective in the inhibition of the growth of the A2780 ovarian         cells, resulting in a statistically significant (P<0.01) tumor         reduction compared to the control group with T/C values of 9.2%         and 22.6% (Day 10) in the two highly-dosed groups. Moreover, the         combination of PM01183 and paclitaxel produced lower T/C values         than the more active single agent in this experiment (paclitaxel         at doses of 25 mg/kg and 18.75 mg/kg). Specifically, the TC (%)         values of the combination (25 mg/kg paclitaxel+0.18 mg/kg         PM01183) vs paclitaxel alone (25 mg/kg paclitaxel) were 28.8 vs         42.9 (day 5), 20.9 vs 34.0 (day 7), and 9.2 vs 19.8 (day 10),         and the TC (%) values of the combination (18.75 mg/kg         paclitaxel+0.135 mg/kg PM01183) vs paclitaxel alone (18.75 mg/kg         paclitaxel) were 37.1 vs 43.2 (day 5), 36.0 vs 41.5 (day 7), and         22.6 vs 31.1 (day 10). Therefore, when PM01183 is combined with         paclitaxel a potentiation of the antitumor activity is clearly         observed.

Additionally, based on the median-effect principle, the combination of PM01183 and paclitaxel resulted in CI values less than 1 (at Fa higher than 0.8), indicating synergism in mice bearing ovarian A2780 xenografted tumors.

-   -   b. The combination treatment of PM01183 and vinorelbine was         effective in the inhibition of the growth of the A2780 ovarian         cells, resulting in a statistically significant (P<0.01) tumor         reduction compared to the control group with T/C values of 8.6%         and 26.8% (Day 9) in the two highly-dosed groups. Moreover, the         combination of PM01183 and vinorelbine produced lower T/C values         than the more active single agent in this experiment         (vinorelbine at doses of 16 mg/kg and 12 mg/kg). Specifically,         the TC (%) values of the combination (16 mg/kg vinorelbine+0.18         mg/kg PM01183) vs vinorelbine alone (16 mg/kg vinorelbine) were         10.9 vs 20.8 (day 5), 10.6 vs 24.5 (day 7), and 8.6 vs 20.0 (day         9), and the TC (%) values of the combination (12 mg/kg         vinorelbine+mg/kg PM01183) vs vinorelbine alone (12 mg/kg         vinorelbine) were 29.6 vs 39.1 (day 5), 31.2 vs 43 (day 7), and         26.8 vs 36.1 (day 9). Therefore, when PM01183 is combined with         vinorelbine a potentiation of the antitumor activity is clearly         observed.

Additionally, based on the median-effect principle, the combination of PM01183 and vinorelbine resulted in CI values of 0.75 (at Fa equal to 0.97), indicating synergism in mice bearing ovarian A2780 xenografted tumors.

-   -   c. The combination treatment of PM01183 and doxorubicin was         effective in the inhibition of the growth of the A2780 ovarian         cells, resulting in a statistically significant (P<0.01) tumor         reduction compared to the control group with T/C values of 21.1%         and 44.9% (Day 10) in the two highly-dosed groups. Moreover, the         combination of PM01183 and doxorubicin produced lower T/C values         than the more active single agent in this experiment         (doxorubicin at a dose of 8 mg/kg). Specifically, the TC (%)         values of the combination (8 mg/kg doxorubicin+0.18 mg/kg         PM01183) vs doxorubicin alone (8 mg/kg doxorubicin) were 32.6 vs         49.8 (day 5), 30.3 vs 48.1 (day 7), and 21.1 vs 39.4 (day 10).         Therefore, when PM01183 is combined with doxorubicin a         potentiation of the antitumor activity is clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and doxorubicin resulted in CI values less than 1 (at Fa higher than 0.8), indicating synergism in mice bearing ovarian A2780 xenografted tumors.

Example 14. In Vivo Studies to Determine the Effect of PM01183 in Combination with Cisplatin and 5-Fluorouracil in Human Gastric Tumor Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of cisplatin and 5-fluorouracil by using a xenograft model of human gastric carcinoma.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was HGC-27 cell line, which was obtained from the European Collection of Cell Cultures (ECACC no 94042256).

HGC-27 cells were grown at 37° C. with 5% CO₂ in Iscove's modified Dulbeco's medium (IDMD). Each animal was subcutaneously implanted on the right flank, using 26G needle and a 1 cc syringe, with 5×10⁶ HGC-27 cells (from in vitro passage 4 in PM01183 and cisplatin study, and passage 6 in PM01183 and 5-fluorouracil study), in mL suspension of 50% Matrigel and 50% serum free medium, without antibiotics.

Tumor measurements and treatment tolerability were performed and determined as disclosed in Example 13.

When tumors reached a volume of about 165.5 mm³ in the study of PM01183 with cisplatin and a volume of about 170 mm³ in the study of PM01183 with 5-fluorouracil, mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor volumen measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Cisplatin and 5-fluorouracil were provided as solutions prepared by diluting the product with 0.9% saline solution for injection to the target final concentration.

In these experiments, PM01183 and cisplatin and PM01183 and 5-fluorouracil treatments, as well as placebo, were intravenously administered once per week up to 2 consecutive weeks on Days 0 and 7. Dose level groups were administered either as single agents or in combination.

Comparison of the median tumor volume in the treatment groups (T) to the median tumor volume in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation and combination index (CI) were determined as disclosed in Example 13.

Table 16 reports the % T/C values obtained with PM01183 and cisplatin both administered as single agents and in combination for each dose level, and FIG. 266 shows the tumor volume evaluation of HGC-27 tumors in mice treated with placebo, PM01183, cisplatin, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 16 % T/C on day Group Dose Test materials 0 3 5 7 10 12 14 G01 10 ml/kg Placebo — — — — — — — (Control group) G02 0.18 mg/kg PM01183 99.6 65.9 55.6 38.7 33.5 24.3 24.3 G03 0.135 mg/kg PM01183 97.9 71.6 59.9 47.8 39.3 37.1 38.3 G04 0.09 mg/kg PM01183 98.6 67.5 67.9 66.1 70.2 60.3 65.0 G05 0.045 mg/kg PM01183 98.9 85.9 83.1 92.1 76.4 81.6 88.5 G06 6.0 mg/kg Cisplatin 97.7 76.1 79.0 75.1 64.4 61.3 72.7 G07 4.5 mg/kg Cisplatin 98.5 90.5 94.5 90.2 75.7 73.7 81.1 G08 3.0 mg/kg Cisplatin 99.0 78.6 80.0 78.7 81.3 82.8 85.1 G09 1.5 mg/kg Cisplatin 99.3 78.1 78.8 82.6 83.5 86.6 89.9 G10 0.18 mg/kg PM01183 95.7 55.0 42.4 22.3 12.9 7.6 4.6 6.0 mg/kg Cisplatin G11 0.135 mg/kg PM01183 99.2 67.7 42.7 28.6 17.3 12.1 9.8 4.5 mg/kg Cisplatin G12 0.09 mg/kg PM01183 99.9 80.0 64.3 45.7 47.2 42.4 56.7 3.0 mg/kg Cisplatin G13 0.045 mg/kg PM01183 99.9 93.3 83.0 75.9 69.3 70.3 80.0 1.5 mg/kg Cisplatin Placebo: as disclosed in table 13.

Table 17 reports the % T/C values obtained with PM01183 and 5-fluorouracil both administered as single agents and in combination for each dose level, and FIG. 267 shows the tumor volume evaluation of HGC-27 tumors in mice treated with placebo, PM01183, 5-fluorouracil, and the corresponding combinations combinations for the groups dosed at the two highest ratios.

TABLE 17 Test % T/C on day Group Dose materials 0 2 5 7 9 12 14 G01 10 ml/kg Placebo — — — — — — — (Control group) G02 0.18 mg/kg PM01183 99.6 78.6 50.9 43.3 41.0 33.0 29.2 G03 0.135 mg/kg PM01183 100.2 81.5 58.7 61.4 60.2 54.6 55.1 G04 0.09 mg/kg PM01183 100.6 90.5 87.6 83.4 82.6 76.7 67.7 G05 0.045 mg/kg PM01183 99.9 84.3 103.2 104.6 103.5 101.6 85.0 G06 50.0 mg/kg 5-Fluorouracil 100.3 81.2 82.3 81.1 75.6 69.6 60.7 G07 37.5 mg/kg 5-Fluorouracil 99.4 86.9 86.9 78.6 73.2 76.7 83.1 G08 25.0 mg/kg 5-Fluorouracil 100.6 89.8 97.0 111.4 102.6 93.9 82.8 G09 12.5 mg/kg 5-Fluorouracil 100.7 81.7 101.3 102.8 98.6 90.5 83.8 G10 0.18 mg/kg PM01183 99.6 73.0 44.2 35.9 31.5 25.3 22.0 50.0 mg/kg 5-Fluorouracil G11 0.135 mg/kg PM01183 100.8 73.4 63.5 53.1 50.6 42.8 51.1 37.5 mg/kg 5-Fluorouracil G12 0.09 mg/kg PM01183 99.6 95.8 97.7 98.9 90.0 74.7 69.9 25.0 mg/kg 5-Fluorouracil G13 0.045 mg/kg PM01183 99.5 80.6 87.3 88.5 99.3 87.1 84.2 12.5 mg/kg 5-Fluorouracil Placebo: as disclosed in table 13.

According to these assays it was found that:

-   -   a. The combination treatment of PM01183 and cisplatin was         effective in the inhibition of the growth of the HGC-27 gastric         cells, resulting in a statistically significant (P<0.01) tumor         reduction compared to the control group with T/C values of 4.6%         and 9.8% (Day 14) in the two highly-dosed groups. Moreover, the         combination of PM01183 and cisplatin produced lower T/C values         than the more active single agent in this experiment (PM01183 at         doses of 0.18 mg/kg and 0.135 mg/kg). Specifically, the TC (%)         values of the combination (6 mg/kg cisplatin+0.18 mg/kg PM01183)         vs PM01183 alone (0.18 mg/kg PM01183) were 12.9 vs 33.5 (day         10), 7.6 vs 24.3 (day 12), and 4.6 vs 24.3 (day 14), and the TC         (%) values of the combination (4.5 mg/kg cisplatin+mg/kg         PM01183) vs PM01183 alone (0.135 mg/kg PM01183) were 17.3 vs         39.3 (day 10), 12.1 vs 37.1 (day 12), and 9.8 vs 38.3 (day 14).         Therefore, when PM01183 is combined with paclitaxel a         potentiation of the antitumor activity is clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and cisplatin resulted in CI values less than 1 (at Fa higher than 0.8), indicating synergism in mice bearing gastric HGC-27 xenografted tumors.

-   -   b. The combination treatment of PM01183 and 5-fluorouracil was         effective in the inhibition of the growth of the HGC-27 gastric         cells, resulting in a statistically significant (P<0.01) tumor         reduction compared to the control group with T/C values of 22.0%         and 51.1% (Day 14) in the two highly-dosed groups. Moreover, the         combination of PM01183 and 5-fluorouracil produced lower T/C         values than the more active single agent in this experiment         (PM01183 at a dose of 0.18 mg/kg). Specifically, the TC (%)         values of the combination (50 mg/kg 5-fluorouracil+0.18 mg/kg         PM01183) vs PM01183 alone (0.18 mg/kg PM01183) were 35.9 vs 43.3         (day 7), 31.5 vs 41.0 (day 9), 25.3 vs 33.0 (day 12), and 22.0         vs 29.2 (day 14). Therefore, when PM01183 is combined with         5-fluorouracil a potentiation of the antitumor activity is         clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and 5-fluorouracil resulted in CI values of 0.78 (at Fa equal to 0.97), indicating moderate synergism in mice bearing gastric HGC-27 xenografted tumors.

Example 15. In Vivo Studies to Determine the Effect of PM01183 in Combination with Gemcitabine in Human Pancreatic Tumor Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of gemcitabine by using a xenograft model of human pancreatic cancer.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was SW1990 cell line, which was obtained from the American Type Culture Collection (ATCC: CRL-2172™).

SW1990 cells were grown at 37° C. with 5% CO₂ in RPMI-1640 medium. Each animal was subcutaneously implanted on the right flank, using 26G needle and a 1 cc syringe, with 5×10⁶ SW1990 cells, from in vitro passage 12, in 0.05 mL suspension of 50% Matrigel and 50% serum free medium, without antibiotics.

Tumor measurements and treatment tolerability were performed and determined as disclosed in Example 13.

When tumors reached a volume of about 210 mm³ mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor volumen measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Gemcitabine was provided as a solution prepared by reconstituting the product with 0.9% saline solution for injection to a concentration of mg/ml stock solution. The gemcitabine stock solution was further diluted with 0.9% saline solution for injection to the target final concentration.

In these experiments, PM01183 and gemcitabine treatment, as well as placebo, were intravenously administered once per week up to 3 consecutive weeks on Days 0, 7 and 14. Dose level groups were administered either as single agents or in combination.

Comparison of the median tumor volume in the treatment groups (T) to the median tumor volume in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation and combination index were determined as disclosed in Example 13.

Table 18 reports the % T/C values obtained with PM01183 and gemcitabine both administered as single agents and in combination for each dose level, and FIG. 268 shows the tumor volume evaluation of SW1990 tumors in mice treated with placebo, PM01183, gemcitabine, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 18 % T/C on day Group Dose Test materials 0 3 6 8 10 13 G01   10 ml/kg Placebo — — — — — — (Control group) G02  0.18 mg/kg PM01183 100.0 74.3 61.3 59.4 56.7 56.1 G03 0.135 mg/kg PM01183 99.6 81.3 71.0 73.1 65.6 63.1 G04  0.09 mg/kg PM01183 101.1 81.5 72.8 68.7 68.4 74.4 G05 0.045 mg/kg PM01183 100.2 83.6 82.8 93.3 82.9 88.1 G06 180.0 mg/kg Gemcitabine 102.2 84.1 73.9 66.1 60.9 59.4 G07 135.0 mg/kg Gemcitabine 102.3 78.3 71.9 63.7 55.4 52.7 G08  90.0 mg/kg Gemcitabine 103.8 70.0 73.8 63.3 55.6 54.8 G09  45.0 mg/kg Gemcitabine 102.3 85.5 70.3 70.5 63.3 64.8 G10  0.18 mg/kg PM01183 102.1 69.7 51.2 46.2 36.0 34.1 180.0 mg/kg Gemcitabine G11 0.135 mg/kg PM01183 100.4 64.6 52.8 51.5 48.9 46.0 135.0 mg/kg Gemcitabine G12  0.09 mg/kg PM01183 98.2 83.2 64.4 59.7 50.6 49.6  90.0 mg/kg Gemcitabine G13 0.045 mg/kg PM01183 97.7 81.6 70.9 68.8 65.9 65.7  45.0 mg/kg Gemcitabine % T/C on day Group Dose Test materials 15 17 20 22 24 28 G01   10 ml/kg Placebo — — — — — — (Control group) G02  0.18 mg/kg PM01183 53.2 47.8 44.2 45.3 44.8 38.9 G03 0.135 mg/kg PM01183 56.3 56.7 56.9 56.5 53.0 51.7 G04  0.09 mg/kg PM01183 74.7 80.7 71.9 75.4 77.3 63.9 G05 0.045 mg/kg PM01183 92.6 86.5 85.1 84.5 85.8 85.4 G06 180.0 mg/kg Gemcitabine 58.5 52.1 49.1 48.6 46.9 39.3 G07 135.0 mg/kg Gemcitabine 54.8 51.2 49.5 48.7 49.8 49.5 G08  90.0 mg/kg Gemcitabine 49.9 47.4 47.6 47.0 45.9 49.2 G09  45.0 mg/kg Gemcitabine 63.1 58.5 58.7 57.3 65.2 59.3 G10  0.18 mg/kg PM01183 34.7 31.6 31.7 28.0 26.0 22.7 180.0 mg/kg Gemcitabine G11 0.135 mg/kg PM01183 42.4 38.2 36.6 34.6 31.5 25.8 135.0 mg/kg Gemcitabine G12  0.09 mg/kg PM01183 47.4 46.0 43.8 49.1 46.0 42.9  90.0 mg/kg Gemcitabine G13 0.045 mg/kg PM01183 57.9 59.9 55.9 54.9 52.1 50.5  45.0 mg/kg Gemcitabine Placebo: as disclosed in table 13.

According to this assay it was found that:

-   -   a. The combination treatment of PM01183 and gemcitabine was         effective in the inhibition of the growth of the SW 1990         pancreatic cells, resulting in a statistically significant         (P<0.01) tumor reduction compared to the control group with T/C         values of 22.7% and 25.8% (Day 28) in the two highly-dosed         groups. Moreover, the combination of PM01183 and gemcitabine         produced lower T/C values than the more active single agent in         this experiment (PM01183 at a dose of 0.18 mg/kg). Specifically,         the TC (%) values of the combination (180 mg/kg gemcitabine+0.18         mg/kg PM01183) vs PM01183 alone (0.18 mg/kg PM01183) were 31.7         vs 44.2 (day 20), 28.0 vs 45.3 (day 22), 26.0 vs 44.8 (day 24),         and 22.7 vs 38.9 (day 28). Therefore, when PM01183 is combined         with gemcitabine a potentiation of the antitumor activity is         clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and gemcitabine resulted in CI values less than 1 (at Fa higher than 0.8), indicating synergism in mice bearing pancreatic SW 1990 xenografted tumors.

Example 16. In Vivo Studies to Determine the Effect of PM01183 in Combination with Temozolomide in Human Brain Tumor Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of temozolomide by using a xenograft model of human brain tumor.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was U87-MG cell line, which was obtained from the American Type Culture Collection (ATCC HTB-14™).

U87-MG cells were grown at 37° C. with 5% CO₂ in Minimum Essential Medium Eagle (MEME). Each animal was subcutaneously implanted on the right flank, using 26G needle and a 1 cc syringe, with 5×10⁶ U87-MG cells, from in vitro passage 5, in 0.05 mL suspension of 50% Matrigel and 50% serum free medium, without antibiotics.

Tumor measurements and treatment tolerability were performed and determined as disclosed in Example 13.

When tumors reached a volume of about 139 mm³, mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor volumen measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Temozolomide was provided as a solution prepared by diluting the product in DMSO 10% in 0.9% saline solution for injection to the target final concentration.

In these experiments, PM01183 and temozolomide treatments, as well as placebo, were administered as follows: PM01183, intravenously once per week up to 3 consecutive weeks, on Days 0, 7 and 14, temozolomide orally, in a daily basis during 8 consecutive days (Days 0 to 7), and placebo was administered following the same schedule as those provided for PM01183 and temozolomide. Dose level groups were administered either as single agents or in combination.

Comparison of the median tumor volume in the treatment groups (T) to the median tumor volume in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation and combination index (CI) were determined as disclosed in Example 13.

Table 19 reports the % T/C values obtained with PM01183 and temozolomide both administered as single agents and in combination for each dose level, and FIG. 269 shows the tumor volume evaluation of U87-MG tumors in mice treated with placebo, PM01183, temozolomide, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 19 Test % T/C on day Group Dose materials 0 2 4 7 9 11 14 16 G01   10 ml/kg Placebo — — — — — — — — (Control group) G02  0.18 mg/kg PM01183 99.8 95.5 64.8 63.2 52.0 44.1 38.5 37.1 G03 0.135 mg/kg PM01183 98.5 90.5 61.2 71.3 67.7 65.3 64.2 63.6 G04  0.09 mg/kg PM01183 97.9 99.5 74.4 85.1 69.4 71.8 74.1 73.5 G05 0.045 mg/kg PM01183 98.2 101.0 80.4 83.8 78.8 77.7 76.7 82.5 G06  3.0 mg/kg Temozolomide 97.1 95.5 67.3 39.4 25.3 22.9 28.4 31.5 G07  1.5 mg/kg Temozolomide 94.1 96.9 75.6 73.0 56.5 59.3 50.0 53.5 G08  1.0 mg/kg Temozolomide 98.2 100.2 65.1 81.2 55.0 63.5 73.1 75.0 G09  0.75 mg/kg Temozolomide 97.7 98.9 76.3 77.3 64.4 63.1 62.8 72.7 G10  0.18 mg/kg PM01183 97.8 95.0 50.9 33.1 21.0 18.3 16.6 17.4  3.0 mg/kg Temozolomide G11 0.135 mg/kg PM01183 98.7 102.4 62.7 42.0 30.3 29.1 29.0 30.9  1.5 mg/kg Temozolomide G12  0.09 mg/kg PM01183 96.2 101.0 79.3 76.1 49.8 51.2 57.6 56.5  1.0 mg/kg Temozolomide G13 0.045 mg/kg PM01183 101 106.0 67.4 73.0 57.8 59.0 69.3 72.2  0.75 mg/kg Temozolomide Placebo: as disclosed in table 13.

According to this assay it was found that:

-   -   a. The combination treatment of PM01183 and temozolomide was         effective in the inhibition of the growth of the U87-MG brain         tumor cells, resulting in a statistically significant (P<0.01)         tumor reduction compared to the control group with T/C values of         17.4% and 30.9% (Day 16) in the two highly-dosed groups.         Moreover, the combination of PM01183 and temozolomide produced         lower T/C values than the more active single agent in this         experiment (temozolomide at doses of 3 mg/kg and 1.5 mg/kg).

Specifically, the TC (%) values of the combination (3 mg/kg temozolomide+0.18 mg/kg PM01183) vs temozolomide alone (3 mg/kg temozolomide) were 18.3 vs 22.9 (day 11), 16.6 vs 28.4 (day 14), and 17.4 vs 31.5 (day 16), and the TC (%) values of the combination (1.5 mg/kg temozolomide+0.135 mg/kg PM01183) vs temozolomide alone (1.5 mg/kg temozolomide) were 29.1 vs 59.3 (day 11), 29.0 vs 50.0 (day 14), and vs 53.5 (day 16). Therefore, when PM01183 is combined with temozolomide a potentiation of the antitumor activity is clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and temozolomide resulted in CI values less than 1 (at Fa higher than 0.8), indicating synergism in mice bearing brain U87-MG xenografted tumors.

Example 17. In Vivo Studies to Determine the Effect of PM01183 in Combination with Irinotecan in Human Lung Tumor Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of iriniotecan by using a xenograft model of human lung cancer.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was H460 cell line, which was obtained from the American Type Culture Collection of Cell Cultures (ATCC ref. HTB-177™).

H460 cells were grown at 37° C. with 5% CO₂ in Dulbecco's modified Eagle's medium (DMEM). Each animal was subcutaneously implanted on the right flank, using 26G needle and a 1 cc syringe, with 5×10⁶ H460 cells, from in vitro passage 10, in 0.05 mL suspension of 50% Matrigel and 50% serum free medium, without antibiotics.

Tumor measurements and treatment tolerability were performed and determined as disclosed in Example 13.

When tumors reached a volume of about 177 mm³, mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor volumen measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Irinotecan was provided in the form of a solution prepared by diluting the product with 5% glucose solution for injection to the target final concentration.

In these experiments, PM01183 and irinotecan treatments, as well as placebo, were intravenously administered as follows: PM01183 once per week up to 2 consecutive weeks, on Days 0 and 7, irinotecan was dosed every 4 days, on Days 0, 4 and 8, and placebo was administered following the same schedule as those provided for PM01183 and irinotecan. Dose level groups were administered either as single agents or in combination.

Comparison of the median tumor volume in the treatment groups (T) to the median tumor volume in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation and combination index (CI) were determined as disclosed in Example 13.

Table 20 reports the % T/C values obtained with PM01183 and irinotecan both administered as single agents and in combination for each dose level, and FIG. 270 shows the tumor volume evaluation of H460 tumors in mice treated with placebo, PM01183, irinotecan, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 20 Test % T/C on day Group Dose materials 0 2 5 7 9 12 G01   10 ml/kg Placebo — — — — — — (Control group) G02  0.18 mg/kg PM01183 114.4 79.6 74.7 75.0 69.1 64.9 G03 0.135 mg/kg PM01183 117.6 77.4 67.5 71.7 66.7 52.9 G04  0.09 mg/kg PM01183 116.9 83.1 83.9 76.9 80.6 84.9 G05 0.045 mg/kg PM01183 108.3 78.7 61.2 67.2 78.8 87.9 G06  50.0 mg/kg Irinotecan 112.1 54.9 34.7 27.5 24.8 22.9 G07  37.5 mg/kg Irinotecan 114.9 51.9 44.0 36.7 35.6 37.0 G08  25.0 mg/kg Irinotecan 112.0 55.6 54.9 49.6 53.1 51.8 G09  12.5 mg/kg Irinotecan 97.5 50.3 44.4 48.6 50.0 51.5 G10  0.18 mg/kg PM01183 117.1 44.3 19.4 13.4 10.9 9.0  50.0 mg/kg Irinotecan G11 0.135 mg/kg PM01183 111.2 51.7 23.8 18.4 15.7 15.3  37.5 mg/kg Irinotecan G12  0.09 mg/kg PM01183 110.0 53.2 38.1 26.6 28.0 27.1  25.0 mg/kg Irinotecan G13 0.045 mg/kg PM01183 109.0 60.4 60.1 56.5 60.0 58.5  12.5 mg/kg Irinotecan Placebo: as disclosed in table 13.

According to this assay it was found that:

-   -   a. The combination treatment of PM01183 and irinotecan was         effective in the inhibition of the growth of the H460 lung         cells, resulting in a statistically significant (P<0.01) tumor         reduction compared to the control group with T/C values of 9.0%         and 15.3% (Day 12) in the two highly-dosed groups. Moreover, the         combination of PM01183 and irinotecan produced lower T/C values         than the more active single agent in this experiment (irinotecan         at doses of 50 mg/kg and 37.5 mg/kg). Specifically, the TC (%)         values of the combination (50 mg/kg irinotecan+0.18 mg/kg         PM01183) vs irinotecan alone (50 mg/kg irinotecan) were 19.4 vs         34.7 (day 5), 13.4 vs 27.5 (day 7), 10.9 vs 24.8 (day 9), and         9.0 vs 22.9 (day 12), and the TC (%) values of the combination         (37.5 mg/kg irinotecan+0.135 mg/kg PM01183) vs irinotecan alone         (37.5 mg/kg irinotecan) were 23.8 vs 44.0 (day 5), 18.4 vs 36.7         (day 7), 15.7 vs 35.6 (day 9), and 15.3 vs 37.0 (day 12).         Therefore, when PM01183 is combined with irinotecan a         potentiation of the antitumor activity is clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and irinotecan resulted in CI values less than 1 (at Fa higher than 0.8), indicating synergism or strong synergism in mice bearing lung H460 xenografted tumors.

Example 18. In Vivo Studies to Determine the Effect of PM01183 in Combination with Dacarbazine in Human Fibrosarcoma Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of temozolomide by using a xenograft model of human fibrosarcoma.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was HT1080 cell line, which was obtained from the American Type Culture Collection (ATCC CCL-121™).

HT1080 cells were grown at 37° C. with 5% CO₂ in Minimum Essential Medium Eagle (MEME). Each animal was orthotopically implanted into gastroecnemius muscle by an intramuscular injection using 26G needle and a 1 cc syringe, with 5×10⁶ HT1080 cells, from in vitro passage 9, suspended in serum free medium, without antibiotics.

Total diameter (tumor+leg) measurements were determined by using digital caliper (Fowler Sylvac, S235PAT). This total diameter and animal body weights were measured 2-3 times per week starting from the first day of treatment.

Treatment tolerability was assessed by monitoring body weight evolution, clinical signs as well as evidences of local damage in the injection site.

When total diameter reached a length of about 11.3 mm, mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Dacarbazine was provided in the form of a solution prepared by diluting the product with 5% glucose solution for injection to the target final concentration.

In these experiments, PM01183 and dacarbazine treatments, as well as placebo, were intravenously administered once per week up to 2 consecutive weeks, on Days 0 and 7. Dose level groups were administered either as single agents or in combination.

Comparison of the median total diameter (tumor+leg) in the treatment groups (T) to the median total diameter (tumor+leg) in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation and combination index (CI) were determined as disclosed in Example 13.

Table 21 reports the % T/C values obtained with PM01183 and dacarbazine both administered as single agents and in combination for each dose level, and FIG. 271 shows the total diameter (tumor+leg) evaluation of HT1080 tumors in mice treated with placebo, PM01183, dacarbazine, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 21 % T/C on day Group Dose Test materials 0 2 4 7 9 11 14 16 G01   10 ml/kg Placebo — — — — — — — — (Control group) G02  0.18 mg/kg PM01183 100 59.3 40.0 26.9 26.7 11.5 21.2 30.6 G03 0.135 mg/kg PM01183 100 63.0 62.9 48.1 36.0 30.2 33.0 41.9 G04  0.09 mg/kg PM01183 100 66.7 57.1 65.4 48.0 42.7 45.8 56.4 G05 0.045 mg/kg PM01183 100 77.8 74.3 94.2 80.0 74.0 80.5 91.1 G06 150.0 mg/kg Dacarbazine 100 40.7 28.6 30.8 44.0 37.5 44.9 57.3 G07 112.5 mg/kg Dacarbazine 100 48.1 34.3 53.8 48.0 37.5 43.2 53.2 G08  75.0 mg/kg Dacarbazine 100 74.1 65.7 69.2 58.7 45.8 46.6 51.6 G09  37.5 mg/kg Dacarbazine 100 51.8 54.3 65.4 61.3 47.9 55.1 62.1 G10  0.18 mg/kg PM01183 100 37.0 22.9 17.3 4.0 10.4 −4.2 1.0 150.0 mg/kg Dacarbazine G11 0.135 mg/kg PM01183 100 29.6 25.7 11.5 −8.0 −17.7 −6.8 7.3 112.5 mg/kg Dacarbazine G12  0.09 mg/kg PM01183 100 37.0 31.4 28.8 52.0 43.7 50.8 64.5  75.0 mg/kg Dacarbazine G13 0.045 mg/kg PM01183 100 55.6 51.4 67.3 70.7 62.5 59.3 62.1  37.5 mg/kg Dacarbazine Placebo: as disclosed in table 13.

According to this assay it was found that:

-   -   a. The combination treatment of PM01183 and dacarbazine was         effective in the inhibition of the growth of the HT1080         fibrosarcoma cells, resulting in a statistically significant         (P<0.01) reduction of total diameter (tumor+leg) compared to the         control group with T/C values of 1.0% and 7.3% (Day 16) in the         two highly-dosed groups. Moreover, the combination of PM01183         and dacarbazine produced lower T/C values than the more active         single agent in this experiment (PM01183 at doses of 0.18 mg/kg         and 0.135 mg/kg). Specifically, the TC (%) values of the         combination (150 mg/kg dacarbazine+0.18 mg/kg PM01183) vs         PM01183 alone (0.18 mg/kg PM01183) were 4.0 vs 26.7 (day 9),         10.4 vs 11.5 (day 11), −4.2 vs 21.2 (day 14), and 1.0 vs 30.6         (day 16), and the TC (%) values of the combination (112.5 mg/kg         dacarbazine+0.135 mg/kg PM01183) vs PM01183 alone (0.135 mg/kg         PM01183) were −8.0 vs 36.0 (day 9), −17.7 vs 30.2 (day 11), −6.8         vs 33.0 (day 14), and 7.3 vs 41.9 (day 16). Therefore, when         PM01183 is combined with dacarbazine a potentiation of the         antitumor activity is clearly observed.

Additionally, based on the median-effect principle, the combination of PM01183 and dacarbazine resulted in CI values of 0.28 (at Fa equal to 0.97), indicating strong synergism in mice fibrosarcoma HT1080 orthotopically implanted tumors.

Example 19. In Vivo Studies to Determine the Effect of PM01183 in Combination with Irinotecan in Human Colorectal Tumor Xenografts

The aim of these studies was to evaluate the ability of PM01183 to potentiate the antitumor activity of irinotecan by using a xenograft model of human colorectal carcinoma.

Female athymic nude mice (Harlan Laboratories Models, S.L. (Barcelona, Spain) were utilized for all experiments. Animals were housed in individually ventilated cages, up to ten per cage in a 12-hour light-dark cycle at 21-23° C. and 40-60% humidity. The mice were allowed free access to irradiated standard rodent diet and sterilized water. Animals were acclimated for at least 5 days prior to tumor implantation with a tumor cell suspension.

The tumor model used in these studies was HT-29 cell line, which was obtained from the American Type Culture Collection (ATCC ref. HTB-38™).

HT-29 cells were grown at 37° C. with 5% CO₂ in Dulbecco's modified Eagle's medium (DMEM). Each animal was subcutaneously implanted on the right flank, using 26G needle and a 1 cc syringe, with 5×10⁶ HT-29 cells, from in vitro passage 10, in 0.05 mL of 0.9% Sodium Chloride for injection.

Tumor measurements and treatment tolerability were performed and determined as disclosed in Example 13. Treatment tolerability was assessed by monitoring body weight evolution, clinical signs as well as evidences of local damage in the injection site.

When tumors reached a volume of about 180 mm³, mice were randomly allocated into the treatments and control groups (N=5-7/group) based on body weight and tumor volumen measurements by using NewLab Oncology Software (version 2.25.06.00).

PM01183 was provided in the form of vials of lyophilized PM01183 cake which was reconstituted with water for infusion to a concentration of 0.2 mg/mL. The PM01183 stock solution was further diluted in 5% glucose solution for injection to the dosing formulation concentrations. Irinotecan was provided in the form of a solution prepared by diluting the product with 5% glucose solution for injection to the target final concentration.

In these experiments, PM01183 and irinotecan treatments, as well as placebo, were intravenously administered as follows: PM01183 once per week up to 3 consecutive weeks, on Days 0, 7 and 14, irinotecan was dosed every 4 days, on Days 0, 4, 8, 12 and 16, and placebo was administered following the same schedule as those provided for PM01183 and irinotecan. Dose level groups were administered either as single agents or in combination.

Comparison of the median tumor volume in the treatment groups (T) to the median tumor volume in the control group (T/C×100%) was used for evaluation of the antitumor efficacy. In addition, potentiation was determined as disclosed in Example 13.

Table 22 reports the % T/C values obtained with PM01183 and irinotecan both administered as single agents and in combination for each dose level, and FIG. 272 shows the tumor volume evaluation of HT-29 tumors in mice treated with placebo, PM01183, irinotecan, and the corresponding combinations for the groups dosed at the two highest ratios.

TABLE 22 Test % T/C on day Group Dose materials 0 3 5 7 10 G01   10 ml/kg Placebo — — — — — (Control group) G02  0.18 mg/kg PM01183 100.4 108.4 86.5 101.1 116.5 G03 0.135 mg/kg PM01183 98.4 106.4 95.3 116.6 115.2 G04  0.09 mg/kg PM01183 98.4 100.9 88.7 121.9 129.8 G05 0.045 mg/kg PM01183 99.8 103.7 100.6 111.1 135.8 G06  50.0 mg/kg Irinotecan 100.1 114.7 93.7 96.1 70.5 G07  37.5 mg/kg Irinotecan 98.4 108.1 97.5 99.2 84.3 G08  25.0 mg/kg Irinotecan 98.8 108.6 97.2 101.4 96.5 G09  12.5 mg/kg Irinotecan 99.0 99.1 90.6 97.4 92.7 G10  0.18 mg/kg PM01183 99.5 101.8 78.3 77.5 51.6  50.0 mg/kg Irinotecan G11 0.135 mg/kg PM01183 98.4 98.0 85.2 85.4 60.7  37.5 mg/kg Irinotecan G12  0.09 mg/kg PM01183 99.7 96.4 71.7 77.0 62.7  25.0 mg/kg Irinotecan G13 0.045 mg/kg PM01183 100.7 104.8 104.3 116.0 98.8  12.5 mg/kg Irinotecan Test % T/C on day Group Dose materials 12 14 17 20 G01   10 ml/kg Placebo — — — — (Control group) G02  0.18 mg/kg PM01183 115.4 123.4 86.7 77.5 G03 0.135 mg/kg PM01183 119.1 121.5 133.1 105.2 G04  0.09 mg/kg PM01183 114.1 109.4 116.1 93.4 G05 0.045 mg/kg PM01183 125.1 109.3 G06  50.0 mg/kg Irinotecan 61.7 51.7 41.4 33.3 G07  37.5 mg/kg Irinotecan 77.4 65.0 58.4 49.4 G08  25.0 mg/kg Irinotecan 79.3 82.5 76.3 60.3 G09  12.5 mg/kg Irinotecan 90.8 89.4 102.6 93.4 G10  0.18 mg/kg PM01183 43.8 30.4 21.7 15.6  50.0 mg/kg Irinotecan G11 0.135 mg/kg PM01183 51.9 40.1 39.2 28.7  37.5 mg/kg Irinotecan G12  0.09 mg/kg PM01183 57.7 50.1 47.2 40.7  25.0 mg/kg Irinotecan G13 0.045 mg/kg PM01183 85.5 90.5 88.1 76.5  12.5 mg/kg Irinotecan Placebo: as disclosed in table 13

According to this assay it was found that:

-   -   a. The combination treatment of PM01183 and irinotecan was         effective in the inhibition of the growth of the U87-MG brain         tumor cells, resulting in a statistically significant (P<0.01)         tumor reduction compared to the control group with T/C values of         15.6% and 28.7% (Day 20) in the two highly-dosed groups.         Moreover, the combination of PM01183 and irinotecan produced         lower T/C values than the more active single agent in this         experiment (irinotecan at doses of 50 mg/kg and 37.5 mg/kg).         Specifically, the TC (%) values of the combination (50 mg/kg         irinotecan+0.18 mg/kg PM01183) vs irinotecan alone (50 mg/kg         irinotecan) were 30.4 vs 51.7 (day 14), 21.7 vs 41.4 (day 17),         and 15.6 vs 33.3 (day 20), and the TC (%) values of the         combination (37.5 mg/kg irinotecan+0.135 mg/kg PM01183) vs         irinotecan alone (37.5 mg/kg irinotecan) were vs 65.0 (day 14),         39.2 vs 58.4 (day 17), and 28.7 vs 49.4 (day 20). Therefore,         when PM01183 is combined with irinotecan a potentiation of the         antitumor activity is clearly observed.

Example 20. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Leukemia Cell Lines

The following agents were evaluated in combination with PM01183: methotrexate, daunorubicin, aplidine, ET-743, PM02734 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

JURKAT and MOLT-4 were the human leukemia cell lines selected for this assay, which were obtained from the American Type Culture Collection (ATCC). JURKAT and MOLT-4 cells were grown in phenol red-free RPMI medium supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts:

-   -   a. In the first set of assays, the relative potency of each         compound against the different cell lines was determined using a         72 hours exposure in vitro cytotoxicity assay.

Briefly, cells were seeded in 96 well microtiter plates at a density of 50000 cells per well in 150 μL of culture medium and incubated for 4-6 hours in drug-free medium before treatment with vehicle alone or test compounds for 72 hours.

After incubation, the cytotoxic effect was evaluated using a MTT reduction assay. 50 μL of MTT solution (1 mg/mL) were added to the wells and incubated for 15-17 hours at 37° C. until formazan crystals were formed. After gently removing the culture medium, DMSO was added to dissolve the insoluble purple formazan product into a colored solution. The absorbance of the wells was quantified by measuring the optical density at 540 nm. Results were expressed as percentage of control cell growth. The EC50 values (half-maximal effective concentration) used for the combination studies were calculated using Prism v5.02 software (GraphPad). EC50 was expressed as molar concentration and represented the mean of at least three independent assays.

The individual EC50 values obtained for each drug are shown in tables 23 and 24.

TABLE 23 EC50 values in molar concentration (M) for each of the agents for the JURKAT tumor cell line. EC50 EC50 EC50 Compound (M) Compound (M) Compound (M) Methotrexate 1.45E−07 Daunorubicin 7.92E−07 Aplidine 1.38E−08 ET-743 6.96E−09 PM00104 4.83E−09 PM01183 1.55E−09 PM02734 5.50E−06

TABLE 24 EC50 values in molar concentration (M) for each of the agents for the MoLT-4 tumor cell line. Compound EC50 (M) Compound EC50 (M) Compound EC50 (M) Methotrexate 4.39E−08 Aplidine 1.27E−09 ET-743 3.84E−09 PM00104 1.55E−09 PM01183 8.57E−10 PM02734 1.44E−05

-   -   b. In a second set of experiments, concentration-response curves         for the agents tested, both alone and in two-drug combination,         were performed, using the same methodology described in the         previous paragraph.

Given the significant differences between the respective EC50 values for PM01183 and the other standard drugs in this study, different ratios of fixed concentrations for the two drugs were used. Normally, the selection of the fixed ratios of concentrations were the equipotent ratio (1:1) at the EC50 value for each drug, and some other ratios representing different percentages of the corresponding EC50 values for each drug above or below it. Using these starting concentrations, constant serial dilutions were performed to generate the concentration-response curves for each set of drugs, alone and in combination.

The effect of the two-drug combination, as compared with the effect of each drug alone, on the viability of tumor cells, was evaluated using the Chou and Talalay method which is based on the median-effect principle (Chou and Talalay, Adv. Enzyme Regul. 1984, 22, 27-55). The median-effect equation: f_(a)/f_(u)=(C/C_(m))^(m) (where C is the drug concentration, C m the median-effect concentration (i.e., IC50, ED50, or LD50, that inhibits the system under study by 50%), f a the cell fraction affected by the drug concentration C, f_(u) the unaffected fraction, and m the sigmoidicity coefficient of the concentration-response curve), describes the relationship between the concentration and the effect of a drug on a given biological system.

Based on this equation, the term “combination index” (CI) is used as a quantitative measure of the degree of drug interactions. The combination index (CI) is determined by the equation:

CI=(C)₁/(C _(x))₁+(C)₂/(C _(x))₂

where (C_(x))₁ is the concentration of drug 1 alone that inhibits an x percentage of a system, (C_(x))₂ the concentration of drug 2 alone that inhibits the same x percentage of the system, and (C₁)+(C)₂ the concentrations of drug 1 and drug 2 that in combination also inhibits an X percentage of the system. CI values were calculated by solving the equation for different values of f_(a) (i.e., for different degrees of cell groth inhibition). CI values of <1 indicate synergy, the value of 1 indicates additive effects, and values >1 indicate antagonism.

Data were analyzed using CalcuSyn software (Biosoft, Cambridge, UK). For statistical analysis and graphs Prism software (GraphPad, San Diego, USA) was used. All the results represent the mean of at least three independent experiments.

The effect of the tested drug combinations on cell proliferation is shown in FIGS. 273-283 :

-   -   Combination of PM01183 with methotrexate. The combination of         PM01183 with methotrexate in JURKAT (FIG. 273 ) cell line         resulted in some synergistic effects (CI<1) at determined         concentrations of both drugs. The effects of PM01183 in         combination with methotrexate in MOLT-4 (FIG. 274 ) cell line         were mostly additive.     -   Combination of PM01183 with daunorubicin. The combination of         PM01183 with daunorubicin in JURKAT (FIG. 275 ) cell line was         additive or synergistic (CI<1) at determined concentrations of         the compounds.     -   Combination of PM01183 with aplidine. The combinations of         PM01183 with aplidine in JURKAT (FIG. 276 ) and MOLT-4 (FIG. 277         ) cell lines resulted in some synergistic effects (CI<1) at         determined concentrations of both drugs.     -   Combination of PM01183 with ET-743. The combination of PM01183         with ET-743 in JURKAT (FIG. 278 ) cell line was additive or         synergistic (CI<1) at determined concentrations of both drugs.         The combination of PM01183 with ET-743 in MOLT-4 (FIG. 279 )         cell line was mostly additive.     -   Combination of PM01183 with PM00104. The combination of PM01183         with PM00104 in JURKAT (FIG. 280 ) cell line was at least         additive resulting in some synergistic effects (CI<1). The         combination of PM01183 with PM00104 in MOLT-4 (FIG. 281 ) cell         line resulted in synergistic effects (CI<1).     -   Combination of PM01183 with PM02734. The combination of PM01183         with PM02734 in JURKAT (FIG. 282 ) cell line was mostly         additive, resulting in some synergistic effects (CI<1) at         determined concentrations of both drugs. The combination of         PM01183 with ET-743 in MOLT-4 (FIG. 283 ) cell line resulted in         synergistic effects (CI<1).

Example 21. In Vitro Studies to Determine the Effect of PM01183 in Combination with Chemotherapeutic Agents on Human Lymphoma Cell Lines

The following agents were evaluated in combination with PM01183: gemcitabine, cytarabine, methotrexate, daunorubicin, ET-743, PM02734 and PM00104 (stock solutions of these compounds prepared in pure DMSO and stored at −20° C.). Additional serial dilutions were prepared in serum-free culture medium to achieve a final 4× concentration. Aliquots of 50 μL of each diluted compound were added per well.

RAMOS and U-937 were the human lymphoma cell lines selected for this assay, which were obtained from the American Type Culture Collection (ATCC). RAMOS and U-937 cells were grown in phenol red-free RPMI medium supplemented with 10% Fetal Bovine Serum (FBS), 2 mM L-glutamine and 100 units/mL of Penicillin-Streptomycin, at 37° C., 5% CO2 and 95% humidity.

The screening was performed in two parts, as previously described in example 20.

In the first set of assays, the individual EC50 values were determined for each drug as shown in tables 25 and 26.

TABLE 25 EC50 values in molar concentration (M) for each of the agents for the RAMOS tumor cell line. EC50 EC50 EC50 Compound (M) Compound (M) Compound (M) Gemcitabine 2.51E−08 Cytarabine 3.64E−08 Methotrexate 5.02E−06 Daunorubicin 3.15E−07 ET-743 9.55E−09 PM00104 4.35E−09 PM01183 1.39E−09 PM02734 1.36E−05

TABLE 26 EC50 values in molar concentration (M) for each of the agents for the U-937 tumor cell line. Com- Com- Com- pound EC50 (M) pound EC50 (M) pound EC50 (M) Gemcita- 3.27E−08 Metho- 2.63E−08 Dauno- 3.04E−07 bine trexate rubicin ET-743 8.62E−09 PM00104 4.50E−09 PM01183 1.03E−09 PM02734 6.85E−06

In the second set of assays, concentration-response curves for the agents tested, both alone and in two-drug combination, were performed. The effects of the drug combinations were evaluated using the Chou and Talalay method as described in the example 20

The effect of the tested drug combinations on cell proliferation is shown in FIGS. 284-296 :

-   -   Combination of PM01183 with cytarabine. The combination of         PM01183 with cytarabine in RAMOS (FIG. 284 ) cell line resulted         in some synergistic effects (CI<1).     -   Combination of PM01183 with methotrexate. The combination of         PM01183 with methotrexate in RAMOS (FIG. 285 ) cell line         resulted in some synergistic effects (CI<1) at determined         concentrations of both drugs. The effects of PM01183 in         combination with methotrexate in U-937 (FIG. 286 ) cell line         resulted in some synergistic effects at determined         concentrations.     -   Combination of PM01183 with gemcitabine. The combination of         PM01183 with gemcitabine in RAMOS (FIG. 287 ) cell line was         additive or synergistic (CI<1) at determined concentrations of         both drugs. The combination of PM01183 with gemcitabine in U-937         (FIG. 288 ) cell line resulted in synergistic effects (CI<1).     -   Combination of PM01183 with daunorubicin. The combinations of         PM01183 with daunorubicin in RAMOS (FIG. 289 ) and U-937 (FIG.         290 ) cell lines were at least additive resulting in some         synergistic effects (Oki).     -   Combination of PM01183 with ET-743. The combinations of PM01183         with ET-743 in RAMOS (FIG. 291 ) and U-937 (FIG. 292 ) cell         lines resulted in synergistic effects (CI<1) at determined         concentrations of the compounds.     -   Combination of PM01183 with PM00104. The combination of PM01183         with PM00104 in RAMOS (FIG. 293 ) resulted in synergistic         effects (CI<1). The combination of PM01183 with PM00104 in U-937         (FIG. 294 ) cell line resulted in some synergistic effects         (CI<1) at determined concentrations of both drugs.     -   Combination of PM01183 with PM02734. The combination of PM01183         with PM02734 in RAMOS (FIG. 295 ) cell line resulted in         synergistic effects (CI<1), while the combination of PM01183         with ET-743 in U-937 (FIG. 296 ) cell line was at least         additive, resulting in some synergistic effects (CI<1) at high         concentrations of both drugs. 

1.-38. (canceled)
 39. A method of treating cancer comprising administering to a patient in need of such treatment an amount of PM01183, or a pharmaceutically acceptable salt thereof, with an amount of paclitaxel that together are therapeutically effective and wherein the cancer to be treated is ovarian cancer.
 40. The method of treating cancer according to claim 39, wherein PM01183, or a pharmaceutically acceptable salt thereof, and paclitaxel form part of the same medicament.
 41. The method of treating cancer according to claim 39, wherein PM01183, or a pharmaceutically acceptable salt thereof, and paclitaxel are provided as separate medicaments for administration at the same time or at different times.
 42. The method of treating cancer according to claim 41, wherein PM01183, or a pharmaceutically acceptable salt thereof, and paclitaxel are provided as separate medicaments for administration at different times.
 43. The method of treating cancer according to claim 39, wherein the cancer is refractory to previous therapy.
 44. The method of treating cancer according to claim 43, wherein the patient is relapsing with progressive disease after previous treatment for ovarian cancer.
 45. The method of treating cancer according to claim 39, wherein the cancer is metastatic.
 46. The method of treating cancer according to claim 39, wherein the cancer is advanced.
 47. The method of treating cancer according to claim 39, wherein administration is every three to four weeks.
 48. The method of treating cancer according to claim 47, wherein administration is every three weeks.
 49. The method of treating cancer according to claim 39, wherein the dose of PM01183 administered in combination with paclitaxel in ovarian cancer is lower than an effective dose of PM01183 administered as a monotherapy in ovarian cancer.
 50. The method of treating cancer according to claim 39, wherein PM01183 is administered in synergistic combination with paclitaxel.
 51. The method of treating cancer according to claim 39, wherein the combination treatment increases the efficacy of the therapeutic effect for treating the ovarian cancer in said patient or minimizes or delays the development of drug resistance.
 52. A method of inhibiting cancer cell growth comprising contacting cancer cells with PM01183, or a pharmaceutically acceptable salt thereof, in synergistic combination with paclitaxel, wherein the cancer cells are ovarian cancer cells.
 53. method of increasing or potentiating the therapeutic efficacy of PM01183 monotherapy in the treatment of ovarian cancer, which comprises administering to a patient in need thereof a therapeutically effective amount of PM01183, or a pharmaceutically acceptable salt thereof, in conjunction with paclitaxel. 